To enable or disable notifications, please follow the instructions below:
Go to the Home screen and tap Cog Wheel in the top right, this will bring you to the settings menu.
Tap on "Notifications"
You will now be presented with the notification options; green is on, grey/white is off.
If you enable push notifications you will also be able to add a notification to alert you when a transaction you have received or sent receives a confirmation on the blockchain.
You can also enable or disable email notifications in a similar manner.