I'm using Timesnapper and it's great. Not only it keeps screenshots for everything, but you can also filter by application while searching for an old website yo

I'm using Timesnapper and it's great. Not only it keeps screenshots for everything, but you can also filter by application while searching for an old website you saw or data that you forgot to save. It needs a lot of storage though. In 50GB you can keep 2-3 months of screenshots.