App Pier is described as 'keyboard-centric application launcher and switcher with strong Touch Bar support' and is an app in the OS & Utilities category. There are three alternatives to App Pier for Mac. The best alternative is BetterTouchTool. It's not free, so if you're looking for a free alternative, you could try Pock or MTMR.
BetterTouchTool is a great, feature packed app that allows you to configure many gestures for your Magic Mouse (1 & 2), Macbook Trackpad and Magic Trackpad (1 & 2) and also Mouse Gestures for normal mice.
Pock can place your macOS Dock inside your MacBook's TouchBar, letting you enjoy your screen in full-size every time! It comes with fully-functional badge support so you will not miss any notification.
My idea is to create a platform for creating plugins to customize the TouchBar. I very much like BTT and having a full custom TouchBar (my BTT preset), and I wanted to create it. It's my first Swift project for MacOS.