There's some money to be made with those apps. Doesn't sound like much - but if the app sells even reasonably well, there could be thousands of dollars at stake. No sense in someone else profiting from your work...

You should talk with Moki (Andrew Welch). I believe he is the best person to talk to about
retaining rights around intellectual property, and possible follow up recourse. You can find him on CigarPass, CigarFamily and CigarSnobs. I'm nore sure about timeframes, but I believe you should act quickly - because if it's unchecked it could become public domain or someone else could lay claim to it.