The best alternatives to Challenged are Trendoline, Rival.ly, and Moro. If these 3 options don't work for you, we've listed a few more alternatives below.
Rival.ly is the first social video sharing app that allows users to compete head-to-head through short/semi-short videos while leaving the victor up to the masses. Users can join in on daily challenges from you...
Start a group. Invite all your friends. Make up a challenge. Complete the challenge as creatively/best as possible. Send it to the group. When everyone send something, rate each other. The highest average rated...