PxKeystrokesForScreencasts - Displays Keystrokes in an overlay window
KeyCastr - KeyCastr lets you easily display your keystrokes while recording screencasts.
Carnac - A utility to give some insight into how you use your keyboard/
Key-mon - Utility to show live keyboard and mouse status for teaching and screencasts.
KeyCastOW - keystroke visualizer for Windows, lets you easily display your keystrokes while recording...
Keystroke Pro - Keypress visualizer for macOS