There are many "walkthrough / information" category App with Chinese title that I don't know where to begin with. There is also an App called "Update WP8 to WP8.1" that just giving out when will the update take place... very lame Apps I think. I think it's time for them to create a "e-book" category and throw those Apps in there.
For now I've learnt to click only those Apps with known company name... so far so good. This is not good for WP environment in general in long term IMO.