To check if there is a newer version of the app you have to:
- Exit the main screen (dashboard) by pressing the back button
- Wait a few seconds
- Run back the app
You will see a message if a newer version is available.
Now you have simply to download the app, open the downloaded package (from the notification bar) and follow the instructions.
You can also download the latest version available clicking on this link. Then delete the app on the device and install the newer version you just downloaded.