Windows Phone is just beginning. In one week it had 20,000 apps, 2 weeks later 50,000 apps, and another 2 weeks later, 60,000 apps! Apple and Android market place has more apps but I'm pretty sire it didn't grow this fast in their beginnings.
That's because all the employees, interns and so on at Microsoft are 'encouraged' to write a Windows Phone app by firing the ones that do not unless they have a note from their line managhttp://tech.slashdot.org/story/12/11/06/0128255/nokia-suspends-its-free-developer-program#er excusing them. Also they MS bloggers, astroturfers etc have to mention the next Halo game - "Halo 5 - Flogging a dead Warthog", which will probably be a "Windows Phone 9" aka "XBox portable" exclusive the way things are going.
Dude, do you honestly think its only Microsoft employees who managed to code up and release 20,000-60,000 apps while still juggling their day job? Have you ever even attempted to write software?