Add your App on Gallery Sharing option.

If you want to add image sharing from gallery option to your application, there is a perfect code for this requirement..

You just need to add these lines to your manifest file on that activity which you want to open when you share image/images from gallery to your application.

<action android:name="android.intent.action.SEND" /> This is for single image

<action android:name="android.intent.action.SEND_MULTIPLE" /> This is for multiple image.

 <activity
            <android:name="PhotoSharingActivity"
            <android:label="@string/title_activity_images_showing"
           <android:screenOrientation="portrait" >
          <intent-filter>
                <action android:name="android.intent.action.SEND" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="image/*" />
            </intent-filter>
            <intent-filter>
                <action android:name="android.intent.action.SEND_MULTIPLE" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:mimeType="image/*" />
            </intent-filter>
        </activity>

And in your Activity's onCreate() add receive the images like this.

Intent receivedIntent = getIntent();
        String receivedAction = receivedIntent.getAction();
        String receivedType = receivedIntent.getType();
        //make sure it's an action and type we can handle
        if(receivedAction.equals(Intent.ACTION_SEND)){
            //content is being shared   
            //sharedImage.setVisibility(View.VISIBLE);
            if(receivedType.startsWith("image/")){
                //handle sent image
                Uri receivedUri = (Uri)receivedIntent.getParcelableExtra(Intent.EXTRA_STREAM);
                if (receivedUri != null) {
                    uriArrayList.add(receivedUri);
                    mAdapter = new MyAdapter(getSupportFragmentManager());
                    viewPager.setAdapter(mAdapter);
                    sharedImage.setImageURI(receivedUri);//just for demonstration
                }
            }
        }
//For multiple images
        if (Intent.ACTION_SEND_MULTIPLE.equals(getIntent().getAction()) && getIntent().hasExtra(Intent.EXTRA_STREAM)) {
            ArrayList list = getIntent().getParcelableArrayListExtra(Intent.EXTRA_STREAM);
            sharedImage.setVisibility(View.GONE);
            for (Parcelable parcel : list) {
                Uri uri = (Uri) parcel;
                Uri[] ur;
                uriArrayList.add(uri);
                String sourcepath=getPath(uri);
                imagePathArrayList.add(sourcepath);
            }
            mAdapter = new MyAdapter(getSupportFragmentManager());
            viewPager.setAdapter(mAdapter);
        }