Long Press by TOKI WOKI.
Write in the above field and hold key to access alternate characters.
Pick letter by:
- using mouse wheel;
- hovering over it with your mouse;
- using arrow keys.
I wrote this plugin because I wanted to be able to insert rare characters as easily as on Android or iOS. I learned pretty quickly after doing it that Mountain Lion already offers such a feature. This is called reinventing the wheel...
Available on GitHub.