The book WebGL Insights is now free to download as a PDF. Go get it.
Many of the articles are, of course, WebGL-centric, but some articles in the Rendering Section have general interest, especially for mobile developers. WebGL is “trailing edge,” in that it’s tied to OpenGL ES 2.0, which is what most mobile devices run. So techniques in that section will run in mobile apps in general. WebGL 2 (not covered in this book) is ES 3.0, basically, and current has 22% phone support and 8% tablet support – tablets don’t get refreshed as rapidly as phones.