When you follow several social networks and blogs, the growing stream can become hard to manage. Summify once promised to select messages likely to matter to a reader and collect them in an email. It used signals such as shared links and reading behavior.
A selection is never neutral
Such a digest can save time. You do not have to scan every post to find a few useful articles. Yet a system decides what appears first. Popular links can get more attention while a quiet but relevant post disappears. The filter helps only if you know what you use it for.
I would start with my own criterion. Do you want industry news, ideas from a small group of experts or personal updates from friends? Those are different collections. Choose sources deliberately and check them at set times. Mix everything into one stream and even a clever filter becomes noise.
The historical tool
Summify is an example from the early social-media years, not a current signup recommendation. The lesson carries over to reading lists, newsletters and feed readers: let technology reduce volume, but keep sight of why a source matters. Sometimes the best filter is following fewer accounts.