What is Android actually doing to optimize apps when you are given the “Optimizing Apps” screen after an upgrade? It’s preprocessing each app so that the OS can preload parts of them ahead of time and make it quicker to load them.
Technical version: It’s producing an “odex” file (“Optimized Dalvik Executable”) from the APKs for each app and pushing that into the Dalvik cache.
What is Android doing when it says “optimizing apps” after a system upgrade?
What? How? Wonder. 