CLCL Lite is a universal launcher.
By double/triple pressing a modifier key (Command/Option), you can launch/activate application. You can also open URL in web browser, and switch last active application.
** CLCL Lite can assign an action to only Command and Option key. **
Usage:
1. Launch CLCL Lite
2. Click CLCL Lite's icon in menu bar
3. Choose "Preferences..." from menu
4. Choose a modifier key you want to register from "Hot Key"
5. Choose an action you want to assign to hot key from "Action"
6. Activate an action to double/triple press a modifier key