diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 1c4b617..dfb0569 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -4,7 +4,7 @@
           android:versionCode="1"
           android:versionName="1.0">
 
-  <uses-sdk android:minSdkVersion="9" />
+  <uses-sdk android:minSdkVersion="31" />
   <uses-feature android:glEsVersion="0x00020000" android:required="true" />
 
   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="18" />
@@ -16,6 +16,7 @@
 
     <activity android:name="android.app.NativeActivity"
               android:configChanges="orientation|keyboardHidden"
+              android:exported="true"
               android:theme="@android:style/Theme.NoTitleBar.Fullscreen">
 
       <meta-data android:name="android.app.lib_name"
diff --git a/a.cmd b/a.cmd
index 4b2b0b6..fac8f60 100644
--- a/a.cmd
+++ b/a.cmd
@@ -54,10 +54,10 @@ if not exist .keystore (
   if ERRORLEVEL 1 exit /b 1
 )
 
-"%JAVA_JDK%\bin\jarsigner.exe" -storepass android -keystore .keystore bin\%APK%.build androiddebugkey >nul
+"%ANDROID_SDK%\build-tools\%BUILD_TOOLS%\zipalign.exe" -f 4 bin\%APK%.build bin\%APK%
 if ERRORLEVEL 1 exit /b 1
 
-"%ANDROID_SDK%\build-tools\%BUILD_TOOLS%\zipalign.exe" -f 4 bin\%APK%.build bin\%APK%
+call "%JAVA_JDK%\bin\java" -jar "%ANDROID_SDK%\build-tools\%BUILD_TOOLS%\apksigner.jar" sign --ks .keystore --ks-key-alias androiddebugkey --ks-pass pass:android bin\%APK%
 if ERRORLEVEL 1 exit /b 1
 
 del /q bin\%APK%.build
diff --git a/jni/Application.mk b/jni/Application.mk
index 650082a..0c0307c 100644
--- a/jni/Application.mk
+++ b/jni/Application.mk
@@ -1,9 +1,9 @@
 # https://developer.android.com/ndk/guides/application_mk.html
 
 NDK_TOOLCHAIN_VERSION := clang
-APP_PLATFORM := android-10
+APP_PLATFORM := android-31
 APP_OPTIM := release
-APP_ABI := armeabi-v7a # arm64-v8a x86
+APP_ABI := x86_64 # armeabi-v7a # arm64-v8a x86
 
 #APP_CFLAGS :=
 #APP_CPPFLAGS :=
diff --git a/jni/main.c b/jni/main.c
index 4af74a5..fb26fce 100644
--- a/jni/main.c
+++ b/jni/main.c
@@ -1,4 +1,5 @@
 #include <jni.h>
+#include <string.h>
 
 #include <EGL/egl.h>
 #include <GLES2/gl2.h>
@@ -168,7 +169,8 @@ static void engine_draw_frame(struct engine* engine)
         return;
     }
 
-    glClearColor(0.258824f, 0.258824f, 0.435294f, 1);
+    // glClearColor(0.258824f, 0.258824f, 0.435294f, 1);
+    glClearColor(1, 1, 1, 1);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
     glUseProgram(engine->shader);
@@ -243,8 +245,6 @@ static void engine_handle_cmd(struct android_app* app, int32_t cmd)
 
 void android_main(struct android_app* state)
 {
-    app_dummy();
-
     struct engine engine;
     memset(&engine, 0, sizeof(engine));