Mobile configuration for Android and iOS devices is almost identical.

• Download the free Rocket.Chat app from Play Store or App Store.
• Open the app and select "Connect to a server".
• Enter https://tortilla.rrz.uni-koeln.de as the server address and click on "Connect"
• The registration form will appear. Please enter your employee account (without @uni-koeln.de!) and your password, click on "Register".