Found an interesting info graphic on How Long Does It Take To Build A Native Mobile App?
From the Post
In a survey of 100 native mobile developers, Kinvey determined that creating a fully functional and polished app takes a team about 18 weeks from start to finish. That includes both front-end design and user interface as well as back-end integration like push notifications, user management and authentication, caching and sharing through social channels.
I know what many app developers are thinking when they hear that: “18 weeks?! Who the hell are these turtle-slow developers?” On the other hand, enterprise developers are probably saying: “18 weeks?! We are only halfway through by that point.”
Original Link here