Interesting. Not a huge fan of marketing it as "Absolutely Free" and not mentioning the charge for multiple accounts.<p>I currently use Checker Plus for Gmail Chrome extension: <a href="https://chrome.google.com/webstore/detail/checker-plus-for-gmail/oeopbcgkkoapgobdbedcemjljbihmemj" rel="nofollow">https://chrome.google.com/webstore/detail/checker-plus-for-g...</a>. Does the job very well.
Just a heads-up, I installed it and signed in with one of my two accounts, but then decided to switch the one free account to my other account. After removing the original account, I wasn't given the option to add in the single free account, only upgrade (I'm guessing there was an assumption in the code that the user would always have one account, and never remove it?). Uninstalling/reinstalling didn't give me the option to re-register, either.
Interesting service. I definitely prefer my e-mail notifications to come right from SeaMonkey, but I could see this being useful for those who don't use a separate mail client and prefer to not have their gmail open in a separate tab 24/7.
I wonder about the example gmail addresses given. Do you own john, paul, george at gmail? I know we should use example.com for URL examples, are there any non-assigned addresses for well-known mail services?