Great idea!
I second the idea to make the whole or partial app database available offline. Including a mobile friendly time stamped version of the local fishing regulations with each location will be a huge bonus. It certainly will require a lot of coding, but it is about time someone came up with this.
I believe that anglers should also know about all of the non sport species, such as sculpins, crayfish, and those creepy lampreys.. And what about including photos of the nymps / insects found in certain locations? I started my own photo-database (most recent one was photos / video of surprisingly LARGE cased caddis, some sort of baetis nymphs and yellow scuds chased around by trout fingerlings in the glacial waters of Garibaldi lake... will post it to youtube some time)
Maybe the people in charge of the fisheries may be interested in funding this app if it will include a user friendly interactive version of go-fish-bc's stocking reports and Rodney's fishing locations
I can also offer to help with any illustrations. Users are less likely to uninstall the app within a few days if they see some sort of minimalistic eye candy. In addition to those generic and un-representative illustrations of the fish that we find on google, real photogenic photos of the fish are also a must.
I was also previously asked to make several very basic info-graphics on local fish types and illustrated fishing methods / equipment set ups on this subject. Here's an example: