Hello :). I have a question regarding your experience with shaders on mobile devices…
So I have been implementing this weekend shaders to generate the clouds (based on Simplex Noise with 10 iterations). On PC it does not look bad, but on Android… 
(with 4 iterations I am getting 4 fps, with 1 iteration I get 15 fps, but both of them seem to look very ugly, both because of the detail level and also there is some patterns which can observed, which I believe comes from floating point precision lowering for GL_ES).
So the lesson I have learned so far is that I should avoid real-time procedurally generated clouds on mobile devices (no fog probably, no fires, etc). But then, since on PC it is running fine, I should probably invest a bit in graphics effects, as it is something which can be an added value to the game at the end… The question is, how to mitigate this for different platforms. Should I create some static image or some pre-rendered scene and use it instead for mobile platforms (the size of the game will increase). Or maybe I should pre-render for all platforms and rather display the things as images? What is you experience with shaders in your games?
P.S(once I finish my experiment with clouds I will share the code)