Kite gives you completions and documentation in Atom, sorted by popularity.
We'll be adding many more features very soon.
You can learn more about the broader Kite product at http://kite.com. As part of this package, you also get the Kite Sidebar, which shows more information as you're working. You can access the Kite Sidebar by launching Kite in your Applications folder.
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.