For wildflowers, 26 flower families can be identified with this app. These families contain 80% of the species in Washington. You will not be able to identify the family of the remaining 20% of the species using this app. Although this app does not identify wildflowers to the species level, it can compliment the Washington Wildflowers app from the UW Herbarium, which helps identify 1014 species.
This app starts with classes of conifers or flowers higher in the hierarchy allowing you to make choices about what you are trying to identify, so that you work your way down through subclasses until you reach the correct family (and, for conifers, correct species). At any level in the hierarchy there are two subclasses to choose from, and you make your choice based on descriptive attributes for each subclass.