Since whitestar_999 suggested an app Norton App Lock, it proves that there are so many good apps which surprisingly are still unknown. Keeping this in mind, I hope I can get an app suggestion for some alternatives, which I desperately need:
Alternative to ShareIt: Boy this chinese app have become so crap. With NSFW video thumbnail and bloat I so want to move away from it. But there doesn't seem to be an app as easy and reliable as ShareIt for data transfer between two Android phones.
File manager with FTP functionality: Currently I have to use a separate FTP app which seems to be quite unstable. Keeps disconnecting while copying files. ES File explorer was a nice app. But like ShareIt, it also became extremely bloat. So I started to use Solid File explorer (even paid version). And while it's extremely good file manager, it lacks hosting the files on FTP (while it can connect to any FTP location).
A good text editor: I thought Notepad++ which I found on Android must be as good as desktop. But I think it's from a different developer, and it have ads, unnecessary permissions and you cant even remove ads by donating.
An app that allows taking screenshot: This is for my dad's new phone ASUS Zenfone Max Pro M1. It lacks a software mechanism to take a screenshot, and my dad finds it difficult to take screenshot using hardware key combo shortcut, not to mention using hardware buttons is injurious to the health of the phone.