В Android O можно установить виджет приложения программным способом.
AppWidgetManager mAppWidgetManager =
context.getSystemService(AppWidgetManager.class);
AppWidgetProviderInfo myWidgetProviderInfo = new AppWidgetProviderInfo();
ComponentName myProvider = myWidgetProviderInfo.provider;
if (mAppWidgetManager.isRequestPinAppWidgetSupported()) {
// Create the PendingIntent object only if your app needs to be notified
// that the user allowed the widget to be pinned. Note that, if the pinning
// operation fails, your app isn't notified.
Intent pinnedWidgetCallbackIntent = new Intent( ... );
// Configure the intent so that your app's broadcast receiver gets
// the callback successfully. This callback receives the ID of the
// newly-pinned widget (EXTRA_APPWIDGET_ID).
PendingIntent successCallback = PendingIntent.createBroadcast(context, 0,
pinnedWidgetCallbackIntent);
mAppWidgetManager.requestPinAppWidget(myProvider, null,
successCallback.getIntentSender());
}
Также ознакомьтесь с официальным документом Google Документация