For hose of you that do not have smart phones there are several decent books, that I use myself all the time as an herbalist to help me idetify and locate certain plants and herbs. The ones I use in particular are:
Peterson Field Guide to Western Medicinal Plants & Herbs [PB,2002] (2002)
A Field Guide to Medicinal Plants and Herbs: Of Eastern and Central North America (Peterson Field Guides) by Steven Foster, James A. Duke and Roger Tory Peterson (Dec 28, 1999)
They each cost around $20 dollars (U.S.) but they are both well worth it, considering that even with the smartphone application, you will often find yourself without wifi or a signal to get reception.
Either way thank you for sharing this Emerald, however it would be lovely if you told us what app store and or cell company this application is compatible with.