Once you've got a photo, the main interface opens. There are two sliders along the top. The top one lets you pick what you want to apply--color filters, lighting effects, and frames--and the bottom shows you your options. For example, the first option is for color filters. Select it and below you get a long slider of filter choices. Tap a filter and see what your photo looks like with it.
Unfortunately, you can only apply one filter and you can't increase or decrease the effect. The only way to apply additional filters is to save out and reopen the photo. That goes for all three. Also, all of the color filters have nondescriptive names, making it a pain to quickly pick your desired result. For example, Sophia is apparently heavy vignetting typical of a toy camera lens.
While most of the color filters are good, the lighting effects are really sort of meh. A lot of them are so distinct that you wouldn't want to use them regularly because they're static and wouldn't look like something that accidentally happened to your photos. Mostly they just overwhelm photos instead of adding to them.
Once you've got your photo how you want it, tap the save icon (the little floppy disk) and you'll get a screen with your finished shot. If you don't like what you've got, you can tap the back arrow to tweak some more, restart from the beginning, or export.
Tapping Export hooks into the Android "intent" feature. That basically means you can export to any sharing/communication app you have on your Android device (Bluetooth, Flickr, Gmail, Facebook, etc.) with that click.