Objective C style guide from the best in the business. At the bottom there are links to style guides from Google, Github and others.
This article lists some very easy to miss bugs. For example, I have seen the microphone permission bug with many apps.
iOS devs at Rap Genius write about how to think about Objective C if you are coming from a web development background.
Marcus talks about the use case for Fetched Property feature of Core Data.
iNVASIVECODE has been expanding iOS expertise since 2008. Training classes broadened developers capabilities and understanding through hands-on learning, close personal attention, and a constantly updated curriculum.
Jess gives an overview of prototyping tools and her experience using tools like Origami, Framejs and Adobe After effects.
A comprehensive handbook “Pixel Pefect Precision” from ustwo studio. Some great app design tips in there. We highly recommend downloading it.
See how Jared designed “Unread for iPad”, gives a good glimpse of the thought process and a different perspective.
Tony lists some common pain points with Android development and solutions for it.
Federico has some great recommendations on implementing web requests in your apps and shows an architectural approach of doing it.
If you are getting complaints that users can’t find your apps in Google play store Cliffe suggests checking the permissions you are asking for.
Android Design Toolkit from Boltmade. Includes - UI components, Nexus 5 line graphic shell, default spacing guideline etc.
If you are tired of resizing image for use in different place, Gaston has a Photoshop script for you.