I've have done this dozens of times without a problem, I have seen it dozens of times in sample code (e.g. stack overflow, with many votes), I don't see the problem really. Only that it could overlap maybe when you switch between different activities within the app. Better would have been maybe to keep it in the activity itself statically, or to put it in the onResume().

So explain to me what could happen? Multiple apps of mine are running with low memory usage and never a crash due to this.