Ask HN: Have you been Challenged lately?

I am asking for your feedback on ios app ChlgClub. Challenge Club provides you ability to challenge your friends on tasks, causes and activities dear to you, while you test your own limits. It's the only platform where you can create, compete, and invite others to join you in the coolest, craziest, entertaining and most extreme challenges. Vist at http://www.chlgclub.com