diff --git a/res/layouts/pages/settings.xml.lua b/res/layouts/pages/settings.xml.lua
index 65c107a5..322b6b51 100644
--- a/res/layouts/pages/settings.xml.lua
+++ b/res/layouts/pages/settings.xml.lua
@@ -1,8 +1,5 @@
 function create_setting(id, name, step, postfix)
     local info = core.get_setting_info(id)
-    if postfix == nil then
-        postfix = ""
-    end
     document.settings_panel:add(gui.template("track_setting", {
         id=id,
         name=gui.str(name, "settings"),
@@ -10,7 +7,7 @@ function create_setting(id, name, step, postfix)
         min=info.min,
         max=info.max,
         step=step,
-        postfix=postfix
+        postfix=postfix or ""
     }))
 end
 
@@ -41,6 +38,6 @@ function on_open()
     create_checkbox("camera.shaking", "Camera Shaking")
     document.langs_btn.text = string.format(
         "%s: %s", gui.str("Language", "settings"),
-        gui.get_locales_info()[gui.get_locale()].name
+        gui.get_locales_info()[core.get_setting("ui.language")].name
     )
 end
diff --git a/src/audio/audio.h b/src/audio/audio.h
index 64fb99e2..cb0d5358 100644
--- a/src/audio/audio.h
+++ b/src/audio/audio.h
@@ -352,52 +352,52 @@ namespace audio {
 
     /// @brief Initialize audio system or use no audio mode
     /// @param enabled try to initialize actual audio
-    extern void initialize(bool enabled);
+    void initialize(bool enabled);
 
     /// @brief Load audio file info and PCM data
     /// @param file audio file
     /// @param headerOnly read header only
     /// @throws std::runtime_error if I/O error ocurred or format is unknown 
     /// @return PCM audio data
-    extern PCM* load_PCM(const fs::path& file, bool headerOnly);
+    PCM* load_PCM(const fs::path& file, bool headerOnly);
 
     /// @brief Load sound from file
     /// @param file audio file path
     /// @param keepPCM store PCM data in sound to make it accessible with Sound::getPCM
     /// @throws std::runtime_error if I/O error ocurred or format is unknown 
     /// @return new Sound instance
-    extern Sound* load_sound(const fs::path& file, bool keepPCM);
+    Sound* load_sound(const fs::path& file, bool keepPCM);
 
     /// @brief Create new sound from PCM data
     /// @param pcm PCM data
     /// @param keepPCM store PCM data in sound to make it accessible with Sound::getPCM
     /// @return new Sound instance 
-    extern Sound* create_sound(std::shared_ptr<PCM> pcm, bool keepPCM);
+    Sound* create_sound(std::shared_ptr<PCM> pcm, bool keepPCM);
 
     /// @brief Open new PCM stream from file
     /// @param file audio file path
     /// @throws std::runtime_error if I/O error ocurred or format is unknown
     /// @return new PCMStream instance
-    extern PCMStream* open_PCM_stream(const fs::path& file);
+    PCMStream* open_PCM_stream(const fs::path& file);
 
     /// @brief Open new audio stream from file
     /// @param file audio file path
     /// @param keepSource store PCMStream in stream to make it accessible with Stream::getSource
     /// @return new Stream instance
-    extern Stream* open_stream(const fs::path& file, bool keepSource);
+    Stream* open_stream(const fs::path& file, bool keepSource);
 
     /// @brief Open new audio stream from source
     /// @param stream PCM data source
     /// @param keepSource store PCMStream in stream to make it accessible with Stream::getSource
     /// @return new Stream instance
-    extern Stream* open_stream(std::shared_ptr<PCMStream> stream, bool keepSource);
+    Stream* open_stream(std::shared_ptr<PCMStream> stream, bool keepSource);
 
     /// @brief Configure 3D listener
     /// @param position listener position
     /// @param velocity listener velocity (used for Doppler effect)
     /// @param lookAt point the listener look at
     /// @param up camera up vector
-    extern void set_listener(
+    void set_listener(
         glm::vec3 position, 
         glm::vec3 velocity, 
         glm::vec3 lookAt, 
@@ -415,7 +415,7 @@ namespace audio {
     /// (PRIORITY_LOW, PRIORITY_NORMAL, PRIORITY_HIGH)
     /// @param channel channel index
     /// @return speaker id or 0
-    extern speakerid_t play(
+    speakerid_t play(
         Sound* sound,
         glm::vec3 position,
         bool relative,
@@ -435,7 +435,7 @@ namespace audio {
     /// @param loop loop stream
     /// @param channel channel index
     /// @return speaker id or 0
-    extern speakerid_t play(
+    speakerid_t play(
         std::shared_ptr<Stream> stream,
         glm::vec3 position,
         bool relative,
@@ -454,7 +454,7 @@ namespace audio {
     /// @param loop loop stream
     /// @param channel channel index
     /// @return speaker id or 0
-    extern speakerid_t play_stream(
+    speakerid_t play_stream(
         const fs::path& file,
         glm::vec3 position,
         bool relative,
@@ -467,49 +467,49 @@ namespace audio {
     /// @brief Get speaker by id
     /// @param id speaker id
     /// @return speaker or nullptr
-    extern Speaker* get_speaker(speakerid_t id);
+    Speaker* get_speaker(speakerid_t id);
 
     /// @brief Create new channel. 
     /// All non-builtin channels will be destroyed on audio::reset() call
     /// @param name channel name
     /// @return new channel index
-    extern int create_channel(const std::string& name);
+    int create_channel(const std::string& name);
 
     /// @brief Get channel index by name
     /// @param name channel name
     /// @return channel index or -1
-    extern int get_channel_index(const std::string& name);
+    int get_channel_index(const std::string& name);
 
     /// @brief Get channel by index. 0 - is master channel
     /// @param index channel index
     /// @return channel or nullptr
-    extern Channel* get_channel(int index);
+    Channel* get_channel(int index);
 
     /// @brief Get channel by name.
     /// @param name channel name
     /// @return channel or nullptr
-    extern Channel* get_channel(const std::string& name);
+    Channel* get_channel(const std::string& name);
 
     /// @brief Get stream associated with speaker
     /// @param id speaker id
     /// @return stream or nullptr
-    extern std::shared_ptr<Stream> get_associated_stream(speakerid_t id);
+    std::shared_ptr<Stream> get_associated_stream(speakerid_t id);
 
     /// @brief Get alive speakers number (including paused)
-    extern size_t count_speakers();
+    size_t count_speakers();
 
     /// @brief Get playing streams number (including paused) 
-    extern size_t count_streams();
+    size_t count_streams();
 
     /// @brief Update audio streams and sound instanced
     /// @param delta time elapsed since the last update (seconds)
-    extern void update(double delta);
+    void update(double delta);
 
     /// @brief Stop all playing audio in channel, reset channel state
-    extern void reset_channel(int channel);
+    void reset_channel(int channel);
     
     /// @brief Finalize audio system
-    extern void close();
+    void close();
 };
 
 #endif // AUDIO_AUDIO_H_
diff --git a/src/core_defs.h b/src/core_defs.h
index f9ff9d9a..789d2100 100644
--- a/src/core_defs.h
+++ b/src/core_defs.h
@@ -29,8 +29,8 @@ inline const std::string BIND_HUD_INVENTORY = "hud.inventory";
 class ContentBuilder;
 
 namespace corecontent {
-    extern void setup_bindings();
-    extern void setup(ContentBuilder* builder);
+    void setup_bindings();
+    void setup(ContentBuilder* builder);
 }
 
 #endif // CORE_DEFS_H_
diff --git a/src/files/files.cpp b/src/files/files.cpp
index 59fa44b1..2ea31a44 100644
--- a/src/files/files.cpp
+++ b/src/files/files.cpp
@@ -34,64 +34,64 @@ void files::rafile::read(char* buffer, std::streamsize size) {
 }
 
 bool files::write_bytes(fs::path filename, const ubyte* data, size_t size) {
-	std::ofstream output(filename, std::ios::binary);
-	if (!output.is_open())
-		return false;
-	output.write((const char*)data, size);
-	output.close();
-	return true;
+    std::ofstream output(filename, std::ios::binary);
+    if (!output.is_open())
+        return false;
+    output.write((const char*)data, size);
+    output.close();
+    return true;
 }
 
 uint files::append_bytes(fs::path filename, const ubyte* data, size_t size) {
-	std::ofstream output(filename, std::ios::binary | std::ios::app);
-	if (!output.is_open())
-		return 0;
-	uint position = output.tellp();
-	output.write((const char*)data, size);
-	output.close();
-	return position;
+    std::ofstream output(filename, std::ios::binary | std::ios::app);
+    if (!output.is_open())
+        return 0;
+    uint position = output.tellp();
+    output.write((const char*)data, size);
+    output.close();
+    return position;
 }
 
 bool files::read(fs::path filename, char* data, size_t size) {
-	std::ifstream output(filename, std::ios::binary);
-	if (!output.is_open())
-		return false;
-	output.read(data, size);
-	output.close();
-	return true;
+    std::ifstream output(filename, std::ios::binary);
+    if (!output.is_open())
+        return false;
+    output.read(data, size);
+    output.close();
+    return true;
 }
 
-ubyte* files::read_bytes(fs::path filename, size_t& length) {
-	std::ifstream input(filename, std::ios::binary);
-	if (!input.is_open())
-		return nullptr;
-	input.seekg(0, std::ios_base::end);
-	length = input.tellg();
-	input.seekg(0, std::ios_base::beg);
+std::unique_ptr<ubyte[]> files::read_bytes(fs::path filename, size_t& length) {
+    std::ifstream input(filename, std::ios::binary);
+    if (!input.is_open())
+        return nullptr;
+    input.seekg(0, std::ios_base::end);
+    length = input.tellg();
+    input.seekg(0, std::ios_base::beg);
 
-	std::unique_ptr<char> data(new char[length]);
-	input.read(data.get(), length);
-	input.close();
-	return (ubyte*)data.release();
+    auto data = std::make_unique<ubyte[]>(length);
+    input.read((char*)data.get(), length);
+    input.close();
+    return data;
 }
 
 std::string files::read_string(fs::path filename) {
-	size_t size;
-	std::unique_ptr<ubyte[]> bytes (read_bytes(filename, size));
-	if (bytes == nullptr) {
-		throw std::runtime_error("could not to load file '"+
-								 filename.string()+"'");
-	}
-	return std::string((const char*)bytes.get(), size);
+    size_t size;
+    std::unique_ptr<ubyte[]> bytes (read_bytes(filename, size));
+    if (bytes == nullptr) {
+        throw std::runtime_error("could not to load file '"+
+                                 filename.string()+"'");
+    }
+    return std::string((const char*)bytes.get(), size);
 }
 
 bool files::write_string(fs::path filename, const std::string content) {
-	std::ofstream file(filename);
-	if (!file) {
-		return false;
-	}
-	file << content;
-	return true;
+    std::ofstream file(filename);
+    if (!file) {
+        return false;
+    }
+    file << content;
+    return true;
 }
 
 bool files::write_json(fs::path filename, const dynamic::Map* obj, bool nice) {
@@ -104,11 +104,11 @@ bool files::write_binary_json(fs::path filename, const dynamic::Map* obj, bool c
 }
 
 std::unique_ptr<dynamic::Map> files::read_json(fs::path filename) {
-	std::string text = files::read_string(filename);
-	try {
-		auto obj = json::parse(filename.string(), text);
+    std::string text = files::read_string(filename);
+    try {
+        auto obj = json::parse(filename.string(), text);
         return obj;
-	} catch (const parsing_error& error) {
+    } catch (const parsing_error& error) {
         std::cerr << error.errorLog() << std::endl;
         throw std::runtime_error("could not to parse "+filename.string());
     }
@@ -123,19 +123,19 @@ std::unique_ptr<dynamic::Map> files::read_binary_json(fs::path file) {
 }
 
 std::vector<std::string> files::read_list(fs::path filename) {
-	std::ifstream file(filename);
-	if (!file) {
-		throw std::runtime_error("could not to open file "+filename.u8string());
-	}
-	std::vector<std::string> lines;
-	std::string line;
-	while (std::getline(file, line)) {
+    std::ifstream file(filename);
+    if (!file) {
+        throw std::runtime_error("could not to open file "+filename.u8string());
+    }
+    std::vector<std::string> lines;
+    std::string line;
+    while (std::getline(file, line)) {
         util::trim(line);
-		if (line.length() == 0)
-			continue;
-		if (line[0] == '#')
-			continue;
-		lines.push_back(line);
-	}
-	return lines;
+        if (line.length() == 0)
+            continue;
+        if (line[0] == '#')
+            continue;
+        lines.push_back(line);
+    }
+    return lines;
 }
diff --git a/src/files/files.h b/src/files/files.h
index eba79a07..5bf79a0a 100644
--- a/src/files/files.h
+++ b/src/files/files.h
@@ -31,20 +31,20 @@ namespace files {
     /// @param file target file
     /// @param data data bytes array
     /// @param size size of data bytes array
-    extern bool write_bytes(fs::path file, const ubyte* data, size_t size);
+    bool write_bytes(fs::path file, const ubyte* data, size_t size);
 
     /// @brief Append bytes array to the file without any extra data
     /// @param file target file
     /// @param data data bytes array
     /// @param size size of data bytes array
-    extern uint append_bytes(fs::path file, const ubyte* data, size_t size);
+    uint append_bytes(fs::path file, const ubyte* data, size_t size);
 
     /// @brief Write string to the file
-    extern bool write_string(fs::path filename, const std::string content);
+    bool write_string(fs::path filename, const std::string content);
 
     /// @brief Write dynamic data to the JSON file
     /// @param nice if true, human readable format will be used, otherwise minimal
-    extern bool write_json(
+    bool write_json(
         fs::path filename, 
         const dynamic::Map* obj, 
         bool nice=true);
@@ -52,21 +52,21 @@ namespace files {
     /// @brief Write dynamic data to the binary JSON file
     /// (see src/coders/binary_json_spec.md)
     /// @param compressed use gzip compression
-    extern bool write_binary_json(
+    bool write_binary_json(
         fs::path filename, 
         const dynamic::Map* obj, 
         bool compressed=false
     );
 
-    extern bool read(fs::path, char* data, size_t size);
-    extern ubyte* read_bytes(fs::path, size_t& length);
-    extern std::string read_string(fs::path filename);
+    bool read(fs::path, char* data, size_t size);
+    std::unique_ptr<ubyte[]> read_bytes(fs::path, size_t& length);
+    std::string read_string(fs::path filename);
 
     /// @brief Read JSON or BJSON file
     /// @param file *.json or *.bjson file
-    extern std::unique_ptr<dynamic::Map> read_json(fs::path file);
-    extern std::unique_ptr<dynamic::Map> read_binary_json(fs::path file);
-    extern std::vector<std::string> read_list(fs::path file);
+    std::unique_ptr<dynamic::Map> read_json(fs::path file);
+    std::unique_ptr<dynamic::Map> read_binary_json(fs::path file);
+    std::vector<std::string> read_list(fs::path file);
 }
 
-#endif /* FILES_FILES_H_ */
\ No newline at end of file
+#endif /* FILES_FILES_H_ */
diff --git a/src/frontend/menu.cpp b/src/frontend/menu.cpp
index 82eff74f..2263bc23 100644
--- a/src/frontend/menu.cpp
+++ b/src/frontend/menu.cpp
@@ -25,7 +25,7 @@ void menus::create_version_label(Engine* engine) {
     auto gui = engine->getGUI();
     auto text = ENGINE_VERSION_STRING+" development build";
     gui->add(guiutil::create(
-        "<label z-index='1000' color='#FFFFFF80' gravity='top-right' margin='4'>"
+        "<label z-index='1000' color='#FFFFFF80' gravity='bottom-left' margin='4'>"
         +text+
         "</label>"
     ));
diff --git a/src/logic/scripting/lua/libfile.cpp b/src/logic/scripting/lua/libfile.cpp
index 22772874..00505141 100644
--- a/src/logic/scripting/lua/libfile.cpp
+++ b/src/logic/scripting/lua/libfile.cpp
@@ -90,9 +90,9 @@ static int l_file_mkdirs(lua_State* L) {
 static int l_file_read_bytes(lua_State* L) {
     fs::path path = resolve_path(L, lua_tostring(L, 1));
     if (fs::is_regular_file(path)) {
-        size_t length = (size_t) fs::file_size(path);
+        size_t length = static_cast<size_t>(fs::file_size(path));
 
-        ubyte* bytes = files::read_bytes(path, length);
+        auto bytes = files::read_bytes(path, length);
 
         lua_createtable(L, length, 0);
         int newTable = lua_gettop(L);
diff --git a/src/logic/scripting/lua/libgui.cpp b/src/logic/scripting/lua/libgui.cpp
index 2b3e8f24..b1aedf9b 100644
--- a/src/logic/scripting/lua/libgui.cpp
+++ b/src/logic/scripting/lua/libgui.cpp
@@ -413,12 +413,6 @@ static int l_gui_get_locales_info(lua_State* L) {
     return 1;
 }
 
-/// @brief gui.get_locale() -> string 
-static int l_gui_get_locale(lua_State* L) {
-    lua_pushstring(L, langs::current->getId().c_str());
-    return 1;
-}
-
 const luaL_Reg guilib [] = {
     {"get_viewport", lua_wrap_errors<l_gui_getviewport>},
     {"getattr", lua_wrap_errors<l_gui_getattr>},
@@ -426,7 +420,6 @@ const luaL_Reg guilib [] = {
     {"get_env", lua_wrap_errors<l_gui_get_env>},
     {"str", lua_wrap_errors<l_gui_str>},
     {"reindex", lua_wrap_errors<l_gui_reindex>},
-    {"get_locale", lua_wrap_errors<l_gui_get_locale>},
     {"get_locales_info", lua_wrap_errors<l_gui_get_locales_info>},
     {NULL, NULL}
 };
diff --git a/src/util/platform.h b/src/util/platform.h
index a53ec40c..1b76d589 100644
--- a/src/util/platform.h
+++ b/src/util/platform.h
@@ -4,9 +4,9 @@
 #include <string>
 
 namespace platform {
-    extern void configure_encoding();
+    void configure_encoding();
     // @return environment locale in ISO format ll_CC
-    extern std::string detect_locale();
+    std::string detect_locale();
 }
 
-#endif // UTIL_PLATFORM_H_
\ No newline at end of file
+#endif // UTIL_PLATFORM_H_
diff --git a/src/util/stringutil.h b/src/util/stringutil.h
index bc67b5a9..3fe22219 100644
--- a/src/util/stringutil.h
+++ b/src/util/stringutil.h
@@ -7,55 +7,55 @@
 
 namespace util {
     /// @brief Function used for string serialization in text formats 
-    extern std::string escape(const std::string& s);
+    std::string escape(const std::string& s);
 
     /// @brief Function used for error messages
-    extern std::string quote(const std::string& s);
+    std::string quote(const std::string& s);
 
-    extern std::wstring lfill(std::wstring s, uint length, wchar_t c);
-    extern std::wstring rfill(std::wstring s, uint length, wchar_t c);
+    std::wstring lfill(std::wstring s, uint length, wchar_t c);
+    std::wstring rfill(std::wstring s, uint length, wchar_t c);
 
-    extern uint encode_utf8(uint32_t c, ubyte* bytes);
-    extern uint32_t decode_utf8(uint& size, const char* bytes);
-    extern std::string wstr2str_utf8(const std::wstring ws);
-    extern std::wstring str2wstr_utf8(const std::string s);
-    extern bool is_integer(std::string text);
-    extern bool is_integer(std::wstring text);
-    extern bool is_valid_filename(std::wstring name);
+    uint encode_utf8(uint32_t c, ubyte* bytes);
+    uint32_t decode_utf8(uint& size, const char* bytes);
+    std::string wstr2str_utf8(const std::wstring ws);
+    std::wstring str2wstr_utf8(const std::string s);
+    bool is_integer(std::string text);
+    bool is_integer(std::wstring text);
+    bool is_valid_filename(std::wstring name);
 
-    extern void ltrim(std::string &s);
-    extern void rtrim(std::string &s);
-    extern void trim(std::string &s);
+    void ltrim(std::string &s);
+    void rtrim(std::string &s);
+    void trim(std::string &s);
 
-    extern std::string to_string(double x);
-    extern std::wstring to_wstring(double x, int precision);
+    std::string to_string(double x);
+    std::wstring to_wstring(double x, int precision);
 
-    extern std::string base64_encode(const ubyte* data, size_t size);
-    extern std::vector<ubyte> base64_decode(const char* str, size_t size);
-    extern std::vector<ubyte> base64_decode(const std::string& str);
+    std::string base64_encode(const ubyte* data, size_t size);
+    std::vector<ubyte> base64_decode(const char* str, size_t size);
+    std::vector<ubyte> base64_decode(const std::string& str);
 
-    extern std::string mangleid(uint64_t value);
+    std::string mangleid(uint64_t value);
 
-    extern int replaceAll(std::string& str, const std::string& from, const std::string& to);
+    int replaceAll(std::string& str, const std::string& from, const std::string& to);
 
-    extern double parse_double(const std::string& str);
-    extern double parse_double(const std::string& str, size_t offset, size_t len);
+    double parse_double(const std::string& str);
+    double parse_double(const std::string& str, size_t offset, size_t len);
 
-    extern std::wstring lower_case(const std::wstring& str);
-    extern std::wstring upper_case(const std::wstring& str);
-    extern std::wstring capitalized(const std::wstring& str);
-    extern std::wstring pascal_case(const std::wstring& str);
+    std::wstring lower_case(const std::wstring& str);
+    std::wstring upper_case(const std::wstring& str);
+    std::wstring capitalized(const std::wstring& str);
+    std::wstring pascal_case(const std::wstring& str);
 
     /// @brief Convert `any_prefix:some_data_id` to `some data id`. Leaves
     /// '_' characters at end of the id.
     /// @param id source id
     /// @return resulting caption or empty string if there's nothing but prefix
-    extern std::string id_to_caption(const std::string& id);
+    std::string id_to_caption(const std::string& id);
 
-    extern std::vector<std::string> split(const std::string& str, char delimiter);
-    extern std::vector<std::wstring> split(const std::wstring& str, char delimiter);
+    std::vector<std::string> split(const std::string& str, char delimiter);
+    std::vector<std::wstring> split(const std::wstring& str, char delimiter);
 
-    extern std::string format_data_size(size_t size);
+    std::string format_data_size(size_t size);
 }
 
 #endif // UTIL_STRINGUTIL_H_