If you have an Android phone I'll suggest you to try the app called Series Guide: https://play.google.com/store/apps/details?id=com.battlelanc...
I use it exactly for that purpose.
According to the page you can sync the info with https://trakt.tv/ (so maybe you're more interested in it than the app) but I found the app really handy, you finish an episode and you flag it on the app, that's it!