Up until recently I was using an App to clean the the Android cache once in a while. If you don't, the device over time get's sluggish, because too many apps store too much data in the cache. Over time this cache can grow to GBs in size.
On the other hand, every single "clean cache App", over time, started showing more and more aggresive advertising. I get that the developer wants to make some money, that's fine. But maybe the money is not enough, so more advertising it is.
Turns out, there is a built-in way in Android to clean the cache. No need for an extra App.
Here is how it works: Go into "Settings":
Click on "Storage":
Click on "Cached data" and confirm the question asking you to "Clear cached data":
That's it, now the cache is small and clean again:
Easy, isn't it? It is not possible to clean the cache just for specific Apps. However I haven't found myself in a position where I wanted to just get rid of the cache for one or a few Apps. I always cleaned the entire cache.