Nice article in The Verge on knowledge engine Wolfram Alpha & its new Pro service & what you can do with it:

 On Wednesday, February 8th, Wolfram Alpha will be adding a new, “Pro” option to its already existing services. Priced at a very reasonable $4.99 a month ($2.99 for students), the new services includes the ability to use images, files, and even your own data as inputs instead of simple text entry. The “reports” that Wolfram Alpha kicks out as a result of these (or any) query are also beefed up for Pro users, some will actually become interactive charts and all of them can be more easily exported in a variety of formats.

At only $4.99 a month, I wish I had a good reason to use it. I’ve been using Wolfram Alpha on the Web for years, & for me, the Wolfram Alpha app on my iPad is great.