Objects is a semantic search app for the Wikipedia. It allows users to choose from 240 types and add filters to query 1.5 million objects. The results can be browsed and the Wikipedia or Freebase page can be opened in Safari or Articles.
Example queries: countries founded before 1/1/1900 that contain "United" in their names, actors born after 1/1/1950, planets with a certain mean temperature, cities with a specific population, ...
Check: http://turbolent.com/ , http://itunes.apple.com/us/app/objects/id410949899 and http://news.ycombinator.com/item?id=2096730
Thanks!
