I don't think I saw OpenStreetMaps in the lists provided by various people in this thread. I rely on GPS a lot, and having a local one would help greatly (preferably on phone, but still).
Weren't it for the fact the current UI is intended more for debug and development (as opposed to Android and iOS versions), Organic Maps would be cool.
Also, OpenLibrary, AniDB / Anilist / Anime-Planet / GoodReads / IMDB / jeuxvideo.com / Last.fm / LibraryThing / MangaUpdates / MyAnimeList / MyDramaList / NovelUpdates / Shikimori / TheTVDB / WLNUpdates (databases of various entertainment stuff).
Then I can look in the GPS where to find them.