I am looking to use one of the social networks in my Android program.

Most important for me is the ability to build a continuous leadership board in which players move up and down depending their wins/loses to others. The idea is for players to challenge others head-to-head. The winner gains points and the loser loses points.

Equally important, I want this feature to include the possibility to "charge" the player game coins.

Scoreloop includes the possibility of challenges but they are there in order to win coins off other players. In other words, they are the means to the end. In my case I need it to be the other way around. The "ends" is to be higher in the leadership board and the "means" are to play others with coins. Scoreloop do have a continuos leadership board but it is not accessible from the program.

I tried looking at OpenFeint but their site is a real mess. It is impossible to understand from there exactly what is and isn't available. I signed up and tried to add my program. I ended up adding it four times and cannot delete it!