Designing mobile applications require a profound understanding of the problem, the audience and the goals of your product. It's a task that involves UX designers, researchers and pretty much everybody that uses that problem.
Another dashboard & sidebar
Checkout screen – User interface by bearduo
12 weeks marathon in Sketch on Behance
Demo screens for a chat app
UI Design: Airwala App / flight travel checker
Airlines, Listen Up: Here's the Boarding Pass You Should Be Using