Your best recommendations for apps, which are not broadly known.

I just discovered IINA video app for Mac, which replaced VLC for me. And as I understood, the app is not that popular in the general public. So I’m looking for suggestions like that

Edit: Summary of suggestions in the post (Thanks to people from reddit):

• The must haves: PopClip and BetterTouchTool
• MenubarX deserves more attention.
• Clocker (World Clock) is free and beautiful.
• SideNotes is a great note taking app that it's not usually mentioned.
• Orion simple security centered browser.
• Zclock floating clock
• VVV drive cataloging (open source http://vvvapp.sourceforge.net)
• Reader (PDF) http://www.liquid.info
• Itsycal. It's basically a tiny calendar in my menu bar. https://www.mowglii.com/itsycal/
• TrashMe 3 is a lightweight and cheaper alternative to the heavily promoted CleanMyMac X app
• OpenIn app is a good replacement for Choosy https://loshadki.app/
• LinearMouse - Automatically sets scrolling behaviour for different input devices. For example, you can have different scroll directions for a trackpad and for a Bluetooth mouse when it connects.
• Hopper - Amazing disassembler and reverse engineering tool that's not widely known, and a bit expensive but worth it.
• TG Pro - Check internal temperatures like CPU, GPU, etc, along with fan control so you can cool down your Mac (works great for my MBP M1 Pro) when it gets too hot.
• Taccy - Check the code signing for any application along with which flags have been set (ex: hardened runtime, sandboxing, etc).

And more recommendations here: https://github.com/svenko99/MacOS-free-apps-gems