I *hate* to say this, but: you can insert Unicode characters *directly* from the keyboard - at least in Windows - without having to use an extension. Just hold down the Alt key, type the Unicode code, and release the Alt key... I use the degree (°) symbol ALL the time - it's 0176. All this, without having to take your hands off the keyboard to grab the mouse, click the button, and type the code.

I gave it 3 stars to be neutral/kind -- because it works, and took work -- but isn't really necessary. (It might be helpful for Mac and/or Linux, I haven't checked, so there's that. However, the description should point out that, for Windows users at least, it actually adds work, and inform them how to do it with the Alt key....

Sorry - trying to be helpful to others, not harsh your buzz. Good-on-ya' for doing the work, anyway.