Userscript for greasemonkey (Firefox)/ tampermonkey (Chrome/Chromium) that causes Gmail to check pop3 boxes more frequently.
This was originally based on Daniel Slaughter's Gmail POP3 Checker scripts, but was reworked to avoid calls out to a server and be completely self-contained.
Basics are working, it has been tested in two different gmail accounts with chrome/chromium on linux using tampermonkey.
Will perform a check immediately when starting up, then start a 3 minute countdown timer until the next check.
If you want to change the length of the timer, change the interval value in the defaults section near the top of the
script.