Quiver is an After Effects script that allows you to apply saved expressions to your layers. It's a huge time saver for me and anyone who uses expressions in their work (hopefully everyone). We've all had the expressions.txt file that we copied and pasted from. I hope you dump it like I did.
Expanding upon the previous version, Quiver 2 allows you to create and modify the txt files containing your library of expressions right from within the panel itself!
If you haven't yet, check out the video above for more information on how it works.
This download comes with the extension, a user guide, and a folder of expressions to use in your projects.