CheatSheet is lets you view available keyboard shortcuts in your current application. Just hold the ⌘-Key a bit longer to get a list of all active short cuts of the current application. It's as simple as that.
Pretzel is Mac desktop app that shows and find keyboard shortcuts based on your current app.
SketchKeys is a sticker set for your keyboard, designed to help you remember every producive Sketch shortcut.
Quickey New Tab is an elegant dashboard of customizable keyboard shortcuts that launch your favorite websites/bookmarks instantly 🚀 and eliminates unnecessary clicking & typing from your workflow ⏳