I've discovered that using a mobile device to take a photograph exercises a different creative muscle than using my large dSLR camera -- and to be honest, I find it more far more difficult, since I'm unable to control things like aperture and ISO, as I would with the Nikon. For this reason, every day I try to capture at least one image with a mobile device (an iPad or iPhone, usually) and upload it to Instagram, just to practice.
These are my most recent shots.
(Click on each image to open them in a lightbox; once they're enlarged, you can hover your cursor over the image to read the caption. And, of course, if you're on Instagram, you can follow me and leave comments at @heychookooloonks!)