other apps that can be run on android shown stretched(also it depends from orientations of screen, in some orientation stretched more). then i try to use https://github.com/Kha-Samples/BlocksFromHeaven where as i understood this situations should be handled. but it not want to run on my snapdragon 210 android.

also can't understood why html projects can't be run on Chrome and Edge but can on Firefox, meanwhile on some other engines webgl runs ok on chrome too

meanwhile this example http://luboslenco.com/kha3d/build/08/ works fine in Chrome, this used Kha too as i understood. may be i make something wrong when build app for html5

error in android studio when it can't be run on emulator too

E/AndroidRuntime: FATAL EXCEPTION: GLThread 50
java.lang.NullPointerException
at haxe.io.BytesInput.__hx_ctor_haxe_io_BytesInput(BytesInput.java:36)
at haxe.io.BytesInput.<init>(BytesInput.java:19)
at kha.audio2.ogg.vorbis.Reader.readAll(Reader.java:74)
at kha.Sound.uncompress(Sound.java:35)
at kha.Assets_loadEverything_113__Fun.__hx_invoke0_o(Assets_loadEverything_113__Fun.java:29)
at kha.SoundList_blocksLoad_136__Fun.__hx_invoke1_o(SoundList_blocksLoad_136__Fun.java:23)
at kha.Assets_loadSound_190__Fun.__hx_invoke1_o(Assets_loadSound_190__Fun.java:27)
at kha.LoaderImpl.loadSoundFromDescription(LoaderImpl.java:71)
at kha.Assets.loadSound(Assets.java:360)
at kha.SoundList.blocksLoad(SoundList.java:61)
at kha.SoundList.__hx_invokeField(SoundList.java:993)
at haxe.lang.Runtime.callField(Runtime.java:521)
at haxe.lang.Closure.__hx_invokeDynamic(Closure.java:27)
at haxe.lang.VarArgsBase.__hx_invoke1_o(VarArgsBase.java:96)
at kha.Assets.loadEverything(Assets.java:252)
at haxe.root.BlocksFromHeaven.__hx_ctor__BlocksFromHeaven(BlocksFromHeaven.java:62)
at haxe.root.BlocksFromHeaven.<init>(BlocksFromHeaven.java:17)
at haxe.root.Main.init(Main.java:44)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at haxe.lang.Runtime.slowCallField(Runtime.java:500)
at haxe.lang.Runtime.callField(Runtime.java:524)
at haxe.lang.Closure.__hx_invokeDynamic(Closure.java:27)
at haxe.lang.VarArgsBase.__hx_invoke0_o(VarArgsBase.java:110)
at kha.SystemImpl.init(SystemImpl.java:209)
at kha.System.init(System.java:85)
at haxe.root.Main.main(Main.java:37)
at kha.SystemImpl.preinit(SystemImpl.java:324)
at com.ktxsoftware.kha.KhaRenderer.onSurfaceCreated(KhaRenderer.java:45)
at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1494)
at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1240)
Application terminated.

a ok related to chrome i understood, it just needed web server. and on my Firefox i think already was installed related webserver plugin that allow to run example

Firefox doesn't need a webserver because it's cross-origin policies do not apply to local files like they do in Chrome. Will try to reproduce your Android issue.