he he, i don't even get a signal where i live
If I had one i'd want an app that works like those toys the kids can get, where it asks you questions and you answer and based on your answer it narrows down what it can be.
Say - Fungi version, is it's basic shape like this?, is it white, is it black, is it on ash, is it hard etc etc It it highly likely that you have king alfed cake.....Deathcap......Chicken of the woods etc
That for Fungi, trees, plants etc would be good. I think you'd still need to have some books on hand to really nail it (unless it's obvious) but it would help.
Also a map app that will allow you to record info - found a good blackberry patch here, lots of hazelnuts in this hidden garden, canoe access here...etc
There's already likely to be a recipe app and a journal one.