Are you planing to support Linux (Smart)Phones? Ubuntu Touch for example. There are others too...
It would be wiser to support Windows (phone). Microsoft is now concentrating on mobile platforms and say also say that future OS would have the ability to run android apps on windows phones.
Also the fact that windows phones currently lack of decent bitcoin wallets I believe that Mycelium could easily lead the windows market.
M$ Phones are not security/privacy acceptable, so not an option.