Rated 4 out of 5 stars

I find this addon really useful but I agree with Icyfer, one thing could improve it.

In the Customize Firesizer dialog there could be a selection box for which corner you want Firefox to stay fixed in and resize from. ie Top Left, Top Right, Bottom Left, Bottom Right

This review is for a previous version of the add-on (1.2.1-signed.1-signed).