I bet it’s Clean Master… at least it’s the most popular cleaning app, and Cheetah do a lot to advertise this placebo crapware. The UI has lots of snappy animations, with turning wheels and launching rockets, but in effect, it does not make anything run any faster. It only deletes some random files and folders, and terminates some apps. So 95% of its “functionality” is pulling a show.
kalistan, if you’re looking for an efficient way to clean your phone, install Disk Usage to identify what’s clogging your sd card(s), then use its built-in delete function, or, if you need more precision, install a file manager to clean the junk manually (I’d suggest Solid Explorer or Total Commander).