Have a service status section in the app. This will allow users to see if there are any ongoing outages etc without having to look at other channels like social media or contact support staff.
This could be broken down into sections like ATM Transactions, Exchange, Top Ups etc with a traffic light system so the it is easy to see at a glance if there are any issues.
This would also help relieve surge of support contacts when there is any outage or issue.