Flies section is very thorough and you can search by name, region, or type. Or browse. Has description of the flies that for the most part are the materials to tie it but they don't go into any info on tying the fly. This would be an excellent addition, instead they have a "buy" symbol.
Knots; this is very cool and provides animated illustrations on tying a lot of different knots. Casting; some good tips and videos.
They have fishing reports but you need your phone to be online to use them. I might not fish by these reports though. I guess I would just question their validity and conditions can change quickly. Like everything, if it is embraced and updated regularly it could be helpful. I see it working for migratory fish liked Stripers and Steelhead much better than say Trout rivers. Trout stream hotspots are often more guarded than the migratory fishes.
OK, back to me. Reading the blurb online, one nice feature seems to be a link to fishing license info for every state, plus all of their regulations. Plus, I got through this whole thing w/o saying "i'm hooked on this" or similar... You can read more reviews and purchase the $14.99 app via iTunes.