public class EntryActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Check to see if this Activity is the root activity
        if (isTaskRoot()) {
            // This Activity is the only Activity, so
            //  the app wasn't running. So start the app from the
            //  beginning (redirect to MainActivity)
            Intent mainIntent = getIntent(); // Copy the Intent used to launch me
            // Launch the real root Activity (launch Intent)
            mainIntent.setClass(this, MainActivity.class);
            // I'm done now, so finish()
            startActivity(mainIntent);
            finish();
        } else {
            // App was already running, so just finish, which will drop the user
            //  in to the activity that was at the top of the task stack
            finish();
        }
    }
}

Config config = new Config("API_KEY", "https://demo.android.filestack.com", "POLICY", "SIGNATURE");

// Create an intent to launch FsActivity
Intent intent = new Intent(this, FsActivity.class);

// Create a config object with your account settings
// Using security (policy and signature) is optional
Config config = new Config("API_KEY", "RETURN_URL", "POLICY", "SIGNATURE");
intent.putExtra(FsConstants.EXTRA_CONFIG, config);

// Setting storage options is also optional
// We'll default to Filestack S3 if unset
// The Filename and MIME type options are ignored and overridden
StorageOptions storeOpts = new StorageOptions.Builder()
    .location("gcs")
    .container("android-uploads")
    .build();
intent.putExtra(FsConstants.EXTRA_STORE_OPTS, storeOpts);

// To manually handle uploading, set auto upload to false
// You can upload the user's selections yourself with the Client class
intent.putExtra(FsConstants.EXTRA_AUTO_UPLOAD, false);

// To customize the sources list, pass in a list of constants
// The sources will appear in the order you add them to the list
// Defaults to Camera, Device, Google Drive, Facebook, Instagram, and Dropbox
ArrayList<String> sources = new ArrayList<>();
sources.add(Sources.CAMERA);
sources.add(Sources.DEVICE);
sources.add(Sources.GOOGLE_DRIVE);
sources.add(Sources.GITHUB);
intent.putExtra(FsConstants.EXTRA_SOURCES, sources);

// Restrict the types of files that can be uploaded
// Defaults to allowing all
String[] mimeTypes = {"application/pdf", "image/*", "video/*"};
intent.putExtra(FsConstants.EXTRA_MIME_TYPES, mimeTypes);

// Start the activity
startActivityForResult(intent, REQUEST_FILESTACK);

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == REQUEST_FILESTACK && resultCode == RESULT_OK) {
        Log.i(TAG, "received filestack selections");
        String key = FsConstants.EXTRA_SELECTION_LIST;
        ArrayList<Selection> selections = data.getParcelableArrayListExtra(key);
        for (int i = 0; i < selections.size(); i++) {
            Selection selection = selections.get(i);
            String msg = String.format(locale, "selection %d: %s", i, selection.getName());
            Log.i(TAG, msg);
        }
    }
}

public class UploadStatusReceiver extends BroadcastReceiver {
    private static final String TAG = "UploadStatusReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        Locale locale = Locale.getDefault();
        String status = intent.getStringExtra(FsConstants.EXTRA_STATUS);
        Selection selection = intent.getParcelableExtra(FsConstants.EXTRA_SELECTION);
        FileLink fileLink = (FileLink) intent.getSerializableExtra(FsConstants.EXTRA_FILE_LINK);

        String name = selection.getName();
        String handle = fileLink != null ? fileLink.getHandle() : "n/a";
        String msg = String.format(locale, "upload %s: %s (%s)", status, name, handle);
        Log.i(TAG, msg);
    }
}

// Be careful to avoid registering multiple receiver instances
if (savedInstanceState == null) {
    IntentFilter intentFilter = new IntentFilter(FsConstants.BROADCAST_UPLOAD);
    UploadStatusReceiver receiver = new UploadStatusReceiver();
    LocalBroadcastManager.getInstance(this).registerReceiver(receiver, intentFilter);
}