Harry Sondre - It does work if you have OneSignal setup and you have the mobile apps created and for iOS devices you have to setup certificates for push notifications through their developer program. For Android you only have to have OneSignal and Firebase. Android is MUCH easier to setup.

Another benefit to Android is that even if you don't have the mobile apps created, Android has Web Push which allows for Push notifications to be delivered through websites including mobile sites. So if you have it setup correctly, you can get push notifications sent to your Android browser for Jot or any other notifications that you enable that are supported by Una. iOS/Webkit hasn't enabled Web Push even though I constantly send feedback about it.