fixed:
06-12 13:18:17.348: W/dalvikvm(26078): threadid=1: thread exiting with uncaught exception (group=0x40adc228)
06-12 13:18:17.348: W/GAV2(26078): Thread[main,5,main]: dispatch call queued.  Need to call GAServiceManager.getInstance().initialize().
06-12 13:18:17.358: E/AndroidRuntime(26078): FATAL EXCEPTION: main
06-12 13:18:17.358: E/AndroidRuntime(26078): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.snowdream.wallpaper/com.snowdream.wallpaper.ImageGridActivity}: java.lang.NullPointerException
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2194)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2229)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3791)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread.access$700(ActivityThread.java:139)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1265)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.os.Handler.dispatchMessage(Handler.java:99)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.os.Looper.loop(Looper.java:154)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread.main(ActivityThread.java:4945)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at java.lang.reflect.Method.invokeNative(Native Method)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at java.lang.reflect.Method.invoke(Method.java:511)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at dalvik.system.NativeStart.main(Native Method)
06-12 13:18:17.358: E/AndroidRuntime(26078): Caused by: java.lang.NullPointerException
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.support.v4.app.FragmentManagerImpl.getFragment(FragmentManager.java:558)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at com.snowdream.wallpaper.ImageGridActivity.onCreate(ImageGridActivity.java:69)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.Activity.performCreate(Activity.java:4531)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1071)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2150)
06-12 13:18:17.358: E/AndroidRuntime(26078): 	... 12 more
06-12 13:18:19.170: W/GAV2(26078): Thread[GAThread,5,main]: Service unavailable (code=1), will retry.