They're all very iOS inspired although maybe that is the point? The first logo is nice and bright but its very generic too as its your standard iOS gloss effect. The second logo has the same background as iCloud it looks too much of a rip off as its one of iOS's core features. I'm sure the texture on the other logos is lifted from iOS too.
The fourth logo is the one I prefer because its bright and you have manipulated the texture in a nice way and interesting way and is more destinctive which is what you want.
Its probably better to present icons at their actual size rather than the huge size as they are currently.