1. Open the app and press "More > Integrations > Custom Shortener"
2. Add the next line: "http://kcy.me/api/?u=USER&key=USERKEY&url=%@"
3. Replace USER by your karmacracy username, and USERKEY by your 3rd party app key (not your password). You can find it in your settings > connections page
4. Press 'OK' and have fun.