You can sign out one device or every other device from "Linked devices" in "User settings", and changing or resetting your password also signs out your other devices.
How do I sign out my other devices on Fluxer?
"Linked devices" in "User settings" lists every device where you're signed in, with its app, rough location, IP address and when it was last used. You can sign out one device at a time or choose "Sign out all other devices" after you confirm it's you.
Changing your password in settings signs out every other device but keeps you signed in on this one. If you reset it with "Forgot your password?", every device is signed out.
If you think someone else has access to your account, change your password and turn on two-factor authentication, then email support@fluxer.com.