Today only Triposo Pro is Free on Google Play - just use code 1ormllk (Number one, orange, ring, milk, lemon, lemon, kilo)
The claim to be the #1 app for people who appreciate spontaneity and serendipity as ways to enjoy travel.
Shared Via The HUKD App For Android.
thanks to dlee1:
1. Register and log into an account in the app (or connect with your Facebook account).
2. Touch the top left menu (where it says "World".
3. Touch "Account".
4. Touch the button to upgrade to Pro.
5. Enter code in "Invitation Code" area.
Once you click the confirm button it will upgrade you account status to pro.