Are any personal trainers on here using Konkura.com

Hi all

New on here and liking it so far - seems some really good / knowledgable people on here. I'm quite new to the all 'online' lark, but have started using a few good sites including this one. I'm into trying new exercises and making it competitive. A guy at my gym told me about http://www.konkura.com/ , Ive been on it a few weeks now and am finding it totally addictive. Ive entered loads of fitness challenges like the 'push-ups in one minute', 'the arm destroyer' and 'are you a marine' ones. I've not created any new challenges of my own yet, but am going to. Most people on there seem to be cool and some know their fitness. I just wondered if any members or personal trainers on here use it to motivate their training and that of their clients? Does anyone know of any similarly good sites I can give a go?