Favs is an app nobody should need. You should be able to flag favorites on social networks and almost instantly find your curated content at a later date, no matter how far into the past it was defined. But back here on Planet Reality, favorites rapidly disappear from view, becoming difficult to find once they’re more than a few days old. And if you engage with several social networks, you have the added complication of remembering which one you should start searching in.
We are increasingly encouraged by social networks to flag things we find online that we like. The Facebook "Like" button is now almost ubiquitous, popping up on myriad websites, but you’ll also find similar functionality in Twitter, YouTube, Flickr, and many other networks.