Did you design the UI yourself? For me (and maybe most programmers) the hardest part of building an application is UI design. You did a really nice job.
I did do it by myself and I really appreciate you saying that. I used/modified a few icons and pictures that I found online though and their awesome creators (who released them under attribution licenses) are credited in the graphics credits section. I struggled a lot with the design and it was by far the most time consuming part of the app.
