There are a couple of reasons why an installed button may not appear in the Thrutu drawer.
- It doesn't have an intent-filter entry in the manifest registering it as a button, the button activity or service must have an intent-filter with a category of "com.thrutu.category.THRUTU" and an action of "com.thrutu.JSI", "com.thrutu.ACTIVITY", or "android.intent.action.PICK".
- The API key is not valid, it must have been generated on the Thrutu developer site with the correct signing certificate and package name.
If you've checked both of these and think they are set up correctly, you can check the Android logs to narrow down why Thrutu isn't offering the button. When you go to the 'Buttons' screen in Thrutu you should see a log like the following for your button:
LauncherFinder found com.thrutu.example.CheeseOnToast.CheeseSender
If this line doesn't appear (for your activity or service) then the intent-filter isn't set up correctly. If this line does appear then there should be a log shortly afterwards saying why the button was rejected (e.g. com.thrutu.example.CheeseOnToast does not have a valid API key).