It means there is 1 review waiting for me that is related to "suggested edits".
This example shows what is shown when I clicked the orange 1:
Down the image there is a compare between old and new (not included) with the name of the editor. The buttons to the right let me aprove or reject it or I can improve it or skip it.
It looks like the system is working in its intended and slightly confusing way.
You only get comment notifications when the system thinks the message is for you
You made a comment that the OP replied to without @'ing you. If you had been the only user apart from the author who commented on that post, you would have been notified (this explains why you've ...
The only Hot Questions feed I can find is the central SE feed. This obviously contains every hot question for every site and every tag. But each item in the feed has enough information to work out what tags apply and what site which means you can process it down.
You could do this with any of a number of tools, but here's a nice simple Yahoo Pipes version:
It is the number of available Suggested Edits to review. But keep in mind that it doesn't refresh automatically.
It reloads when you refresh or you go another page.
So if there was a 1 next to the review button and you had the page open for a while, once you click the 1, there is a chance that there won't be anything to review.
I am now receiving notifications. I realized that I had created an account on Ask Ubuntu without creating one for Stack Exchange itself. It seems that, after creating a Stack Exchange account, I was able to get notifications. As dumb as it is that I didn't do it before, I hope this helps others.
You could probably just forward your own e-mails.
Set it up so you get e-mail reminders for all the things.
In Users → Preferences → Emails
In the account you have setup for e-mail, just have all mail forwarded to your main e-mail address, or a e-mail you have set up to send you mobile reminders.
Also under each question is this: