I wanted to announce that Boletus, the mushroom search engine, is now available via web, and as an Android application. Answer questions about the mushroom you have just found, and check which types are similar to the one described.
Hopefully someone who really knows their mushrooms will take a critical look at these apps. I don't have an IPhone or Android, but when I borrowed a friends a couple of years ago, I found out on a fairly brief perusal that it would have been easy to kill yourself with the wild mushroom "app" then available. Another app had an odd hodgepodge of American and Australian mushrooms together!
Companion Planting Guide by World Permaculture Association