If you're just logging out on the desktop from the Sync preferences, it's the same thing on iOS — you can just log out in the iOS app and log in to the other account.
If you're referring to using multiple profiles on the desktop, there's currently nothing like that in the iOS app.
Can Zotero for iOS remember information about multiple accounts, the usernames and passwords, and configured webdav servers, so that you don't need to re-enter them each time you switch users?
Upgrade Storage
If you're just logging out on the desktop from the Sync preferences, it's the same thing on iOS — you can just log out in the iOS app and log in to the other account.
If you're referring to using multiple profiles on the desktop, there's currently nothing like that in the iOS app.