java - Multiple Instances of Android Application open - ONLY on Touchwiz -

i have been working on application android devices - , have noticed perplexing issue occurs on devices running samsung touchwiz!

when application running on touchwiz device bug occurs. bug can reproduced pressing "back" button while application in foreground - , launching again home screen (or anywhere else icon may be). looking in multi-tasking menu clear system launches second instance of application! second instances totally independent first instance , 2 not seem connected in way.

i thought prevent behavior adding singleinstance applications manifest, did not appear trick. manifest:

  <application     android:allowbackup="true"     android:icon="@mipmap/ic_launcher"     android:label="@string/app_name"     android:supportsrtl="true"     android:theme="@style/apptheme"     android:launchmode="singleinstance">     <activity         android:name=".mainactivity"         android:screenorientation="portrait"         android:launchmode="singleinstance">          <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.default" />         </intent-filter>      </activity>     <activity         android:name=".settings_area"         android:screenorientation="portrait" />     <!--          api key google maps-based apis defined string resource.          (see file "res/values/google_maps_api.xml").          note api key linked encryption key used sign apk.          need different api key each encryption key, including release key used          sign apk publishing.          can define keys debug , release targets in src/debug/ , src/release/.      -->     <meta-data         android:name="com.google.android.geo.api_key"         android:value="aizasydiextcafoil0kj_im4umbsql3snn92awm" />      <activity         android:name=".mapsactivity"         android:label="@string/title_activity_maps" />     <activity android:name=".splash"         android:launchmode="singleinstance">          <intent-filter>             <action android:name="android.intent.action.main" />              <category android:name="android.intent.category.launcher" />         </intent-filter>      </activity>     <activity android:name=".aboutpageactivity" />     <activity android:name=".turnofffromnotification"         android:nohistory="true"></activity> </application> 

it interesting note second instance "freezes" @ applications splash screen - until second instance clicked multi - tasking menu.

this how handling splash screen:

 new handler().postdelayed(new runnable(){         @override         public void run() {             /* create intent start menu-activity. */             intent mainintent = new intent(splash.this,mainactivity.class);             splash.this.startactivity(mainintent);             splash.this.finish();         }     }, splashdisplaylength); 

i over-rode buttons action in main activity:

public void onbackpressed() {     movetasktoback(true); } 

this bug only occurs on devices touchwiz. have tested application on several devices , bug not able reproduced on device except samsung devices running touchwiz.

any suggestions appreciated.

thank much!

the issue seems intent filters in mainactivity. remove intent filters mainactivity solve issue.