If you run into issues, try these solutions to known problems.
If you're using iCloud and find your sites have disappeared after an upgrade to iOS 7, you may be able to manually switch back to your old sites. I've outlined the procedure using screenshots:
Don't hesitate to send us a message at masterpassword@lyndir.com. I'll get right on your case. Try to include any details you can. Even better, use the feedback (mail) button from within the app instead and include logs when prompted.