[herval]

I'm not sure that's such a great advice... I have some friends who ARE doing a fitness app (gympact) and they seem to be doing pretty well there (it's an exercise tracking/incentive app)

For the record, I've been in your shoes before. Started a mobile games company back in 2002, struggled for 3 years with almost no sales at all and had to shut down. Met a first-time founder in 2009 who had this idea of "opening a mobile gamung company" and advised him wholeheartedly about not going there. He's now hiring his 30th employee, making millions every month (and didn't even take VC money to start)...

TL;DR: it didn't work for you, but it CAN work for someone else...

[JofArnold]

You're totally right of course. I should clarify this (as I mentioned somewhere else on this page I think) by saying "I personally can't see a billion dollar opportunity in this space, but it doesn't mean there isn't one".