For both Android and Apple iOS you can download the "Rocket Chat" app in their associated App Store.
When downloaded, installed and started on your device, select "connect to server"
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You will find the chat username and password on your CEPT user profile page, near the bottom: https://www.cept.org/ecc/start-page/profile/
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!! PLEASE NOTE !!
It is possible to change the password directly on the Chat system by either using "Forgot password" on the login form, or in the profile settings on the chat system.
By changing the password directly in the chat system, this will invalidate the password shown at the profile settings on the CEPT portal. Please contact ECO in case you need assistance.
It is NOT possible to create an account from the frontpage of the chat system, all accounts are created based on your CEPT profile.