Like anything on the street and see how many people liked it before you, or what other people say about it. App info is currently processing and/or the app is not yet fully available for sale on the US App Store.
It seems, many people still miss the point of this application and believe, it is a Facebook instant camera. We are working on new features to improve it and give people an extraordinary experience, that they don't get in other applications. We are working on more interactivity, so people can feel being connected even more with other users. For example there will be a "news ticker" which will show the last "like" anywhere in the world and by clicking it, everybody can see the picture and the coordinates, where it was taken. We are also fixing some bugs. Watch out for the next and the overnext release! Use it everywhere every time and fill our database, so everybody always have to like something!
The last update yesterday got rid of the IAP option for "Likes". Now you can buy out the advertisement with IAP, but you don't pay for basic functionality.