MultiImageSelector

<activity
    android:configChanges="orientation|screenSize"
    android:name="me.nereo.multi_image_selector.MultiImageSelectorActivity" />

Intent intent = new Intent(mContext, MultiImageSelectorActivity.class);

// whether show camera
intent.putExtra(MultiImageSelectorActivity.EXTRA_SHOW_CAMERA, true);

// max select image amount
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_COUNT, 9);

// select mode (MultiImageSelectorActivity.MODE_SINGLE OR MultiImageSelectorActivity.MODE_MULTI)
intent.putExtra(MultiImageSelectorActivity.EXTRA_SELECT_MODE, MultiImageSelectorActivity.MODE_MULTI);

startActivityForResult(intent, REQUEST_IMAGE);

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == REQUEST_IMAGE){
        if(resultCode == RESULT_OK){
	        // Get the result list of select image paths
            List<String> path = data.getStringArrayListExtra(MultiImageSelectorActivity.EXTRA_RESULT);
            // do your logic ....
        }
    }
}

class CustomerActivity extends Activity implements MultiImageSelectorFragment.Callback{
	@Override
    protected void onCreate(Bundle savedInstanceState) {
		// customer logic here...
		Bundle bundle = new Bundle();
        bundle.putInt(MultiImageSelectorFragment.EXTRA_SELECT_COUNT, mDefaultCount);
        bundle.putInt(MultiImageSelectorFragment.EXTRA_SELECT_MODE, mode);
        bundle.putBoolean(MultiImageSelectorFragment.EXTRA_SHOW_CAMERA, isShow);
        // Add fragment to your Activity
        getSupportFragmentManager().beginTransaction()
                .add(R.id.image_grid, Fragment.instantiate(this, MultiImageSelectorFragment.class.getName(), bundle))
                .commit();
	}
	@Override
    public void onSingleImageSelected(String path) {
        // When select mode set to MODE_SINGLE, this method will received result from fragment
    }

    @Override
    public void onImageSelected(String path) {
        // You can specify your ActionBar behavior here 
    }

    @Override
    public void onImageUnselected(String path) {
        // You can specify your ActionBar behavior here 
    }

    @Override
    public void onCameraShot(File imageFile) {
        // When user take phone by camera, this method will be called.
    }
}