My first Android App, because i needed a very small and fast ticket app for public transport. There´s only one thing this app can do: Send a specific message to a specific number. It only takes 44kB on your smartphone and additonal 4kB for the settings (number/message).
The “Back” Button closes the App, even if you are on the settings page. That´s not intentional, i just didn´t want to create a new Activity for the settings dialog 🙂