Looking through my Applications folder (all prices in US $) …
Note that I’ve collected these apps over a number of years, and there is some duplication of functionality. And while they might be on my hard drive, they might not be in active use. I am definitely an app collector. 
Perhaps you will find something useful, happy browsing!
Actions Additional actions for the Shortcuts app (free)
AltTab AltTab brings the power of Windows’s “alt-tab” window switcher to macOS. (free)
Amphetetamine Keep your Mac awake. (free)
AppCleaner AppCleaner is a small application which allows you to thoroughly uninstall unwanted apps. (free)
Browsers Open the right browser at the right time. (free)
Bunch Bunch is a utility that uses plain text scripts called “Bunches” to automate context switching. (free)
Button Creator Create Key images quickly. ($3.99)
ClipTools Clipboard Manager and More (free)
CodeRunner A lightweight, multi-language programming text editor and IDE for macOS. ($19.99)
CotEditor The Plain-Text Editor for macOS. (free)
CustomShortcuts Customize Mac Menu Keyboard Shortcuts (free)
DB Browser A high quality, visual, open source tool to create, design, and edit database files. (free)
Desktop Curtain Hide your clutter. ($5)
DevToys Swiss Army knife for developers (free)
DIM Memorizes and restores icon positions. (free)
Finder Windows Access macOS Finder windows easily ($9.95)
HotKey A macOS app for simple keyboard shortcuts (free)
iTerm A replacement for Terminal. (free)
Karabiner A powerful and stable keyboard customizer for macOS. (free)
Key Codes Utility that displays the key code, unicode value, and modifier keys state for any key combination you press. (free)
Keymou Keyboard Mouse ($5)
Notenik Do More With Your Notes (free)
OpenInTerminal Select in Finder, open in Terminal (free)
Paletro Command Palette in any applications on macOS ($6.99)
Permute Easy to usemedia converter, ($14.99)
Platypus Tool that creates native Mac applications from command line scripts. (free)
Popclip Text selection tool. ($16.99)
PowerMenu Workflow enhancing Finder extension. ($9.99)
Printopia Wireless printing to any printer. ($19.99)
rcmd Reimagined Command-Tab. ($5.99)
Reflex Reflex takes control of your media keys, and directs them to the app of your choosing, as long as that choice is Music (née iTunes) or Spotify. (free)
Shareful Give the macOS share menu superpowers. (free)
Shortery Shortcut Automation for your Mac. ($5.99)
SQLiteStudio Create, edit, browse SQLite databases. (free)
SwiftQuit Close Mac Applications Automatically When Their Windows Close (free)
Swish Insanely great window management. ($16)
Touch Portal Touch Portal: The macro multi action remote control. ($13.99)
Übersicht Desktop widgets in Javascript. (free)
Unclutter A new space on your desktopt organize your Files, Notes and Clipboard data ($19.99)
WhiccSpace Menubar space indicator (free)
Yoink Improved Drag and Drop ($8.99)
Inspired by posts like this one: