If you are aware of this not hard to manage. Grep. rm -rf. Done. Usually its pretty tiny folders at least. Heavier stuff usually software makes a directory under Documents. Kinda nice in a few cases having it set up like this. For example I can delete the app but preserve my config. Drop the app right back again and no setup its turnkey and works.
grep for what? How am I supposed to know that the Foo app installed stuff under ~/Libraries/Application Support/com.bar.corporation?