hey antonio,
I just checked your site and was able to replicate the issue. btw, the problem wasn't only happening on the phone but also using my mac.
anyways, the reason this re-direct problem occured was because you had no public menu item for easysocial, the re-direct is trying to forward to an easysocial page that is only available for "registered" users and as someone registering (guest) is not allowed there you were in a loop.

I swtiched your play to play menu item to public and then registered using my iphone - everything went fine and I already received the confirmation mail from your site. please re-check at your end and let me know if that's not solved for you as well.

have a nice day