How to design a successful ios application?

Question

iOS

I have little experience in developing ios applications. More or less I know objective-c, I can partially juggle the main frameworks from cocoa touch, I know oops, some patterns. The problem is the following: I can't find a job as a junior ios developer, the dialogue with the employer ends after completing the test task. I feel my weakness in the field of planning the architecture of a mobile application. I think so, because I often catch myself thinking that the solution that I applied is a hard crutch, but I can’t think of anything better.
Advise, please, what-thread the literature on development of architecture of mobile applications.
PS Can anyone experienced see my projects and tell me what I did wrong :)?