Mega Congrats! Any chance of developing a similar app (paid would be fine) for identifying wildflowers? I have thousands of pictures of wilderness areas across the Western US, and I get tired of saying "and here's an example of... a yellow flower I saw a lot of that day" :-)
We've thought about flowers, but since they are present on trees for a much shorter time than leaves, it would be less useful overall. Since we're somewhat constrained in our resources (most of the work has been done on a volunteer basis), we're focusing on expanding coverage first rather than integrating additional cues for recognition (which will be a very tricky computer vision problem that will likely require a lot of effort).
