I've released the second version of hashr extension for Firefox. This version is a major code fix, since the previous version, 0.1, had global variables and functions declared in a way that could cause conflict with other extensions or sites.
This problem in the code was detected by a sandbox reviewer at the addons mozilla site. Because of this problem, the extension is still retained in the sandbox. Now it's fixed, the functions and variables are in their own namespace, avoiding conflict. So, probably soon it will be out of the sandbox :)
I've also received by mail some suggestions to implement/change things in hashr. They aren't forgotten, it's just too soon to release them.