Browser add ons similar to stumbleupon

I used to have stumbleupon from Firefox but rid of it because there’s only so much you can give daily attention to with computers/internet as the possibilities are almost to choose from. I tried to get it back today and I can’t log in and ‘session timed out’ when I try to get my password/username. I was wondering if some other company has come up with a similar add on or app such as Google, etc.?

Stumbleupon still appears to be very active - maybe just make a new username? You can also link it to your Facebook.