I tried this on Secret Server and the oVirt admin UI, it didn't work on either one. I had the refresh interval set to 1 minute, it still logged me out.

I only need this plugin for one particular site, and the plugin keeps saying that no rules are running on the site, even after creating rules using the Add button.

Doesn't work for me, neither in foreground nor background mode

Honestamente: todos os sites que tinham as sessões encerradas continuaram encerrando as sessões.

keeps abusing firefox stupid ability to send notifications even when browser is not in focus.

Probably works for some sites, but did not work for the site I downloaded it for. Enabling the HEAD for JS did not fix. I still got the timeout messages and would be logged out due to inactivity. Will keep looking for another plugin.

I tried everything but it didn't work for me

Did not work for me. I tried it on two sites.