The most exciting thing about Drop Cache for me is that it is really able to solve some 'slow visual performance' issues on N9 sometime. (I am the author, and an originally primary target of the app was mostly to do some performance tests/measurements only).

I did not believe to users feedback (I thought it works like placebo pills) before I have tried it with a very sluggish animation between Home screens (I have closed every application before - without any improvement). 'Drop Cache' somehow solves such issue.

From my point of view - there is some low level bug somewhere in the kernel, or perhaps some wrong configuration for cgroups, or something like that - and it is just resetted by such 'drop cache' action. It would be nice if it would be possible to do such reset without full cache reset - perhaps I will try to dig in deeper later. (But it is really hard to reproduce the problem).

Yes, more battery consumption at idle state, even some visible delay if user is doing something (like playing in a game) for short period of time, and so on.

Anyway, I will try to update the application later, with some warning to user, perhaps do it at idle state + charging state only, and so on.