If you're unable to disconnect the wrong Facebook account in the Ripl app, please click this link and logout of Facebook (tap the “hamburger” icon in the top right corner, scroll to the bottom and tap log out). Tap "done" to return to the Ripl app menu. Go to "Account Settings" and tap "connect" next to Facebook. You should see the option to login with your Facebook app or phone/email.
If that doesn't work, uninstalling and reinstalling the Ripl app should allow you to login to the correct Facebook account.