By clicking on the person-sign in the upper left corner of the main page, you will be redirected to the account settings.
This overview of your account settings does not only show you how much quota you are already using and how much is still available (circle-bar) but is also listing your username as well as first and last name. You can change the latter two by clicking on them and entering new names. You can also add a phone number, change your e-mail-adress or add a new adress. Furthermore all groups you are a member of will be listed as well and you can configure the settings for the biometric authentication and mobile data. To log out of the app you simply have to click on Log out.