You can copy and paste images into Snapseed, in addition to choosing to activate the camera or to pick an existing photo from your camera roll.
With a photo on the Snapseed screen, choose an editing mode from the tiled menu, and graphical instructions will overlay the photo. Changing a photo's brightness or applying another effect generally involves tapping the screen or swiping a finger across it in one direction or another until the photo looks . . . just right.
Categories of effects include straightening, cropping, framing and automatic adjustments. There are lots of choices - an array that many other apps charge additional fees to enable. When you're satisfied with the look of a photo, save it as a new photo in the camera roll or tap to share, copy or open it in another photo or storage app you might have on your phone, such as Instagram or Dropbox.
KitCam is a $1.99 iPhone app from GhostBird Software. Its advantage over the camera software your phone came with is a display of powerful tap-and-shoot features such as continuous shooting, time-lapse, multi-shot layouts, and exposure controls that will make you feel like you're in heightened control.
Picture-altering effects on KitCam can be added at the time of shooting, rather than later. What you do is tap to pull up a selection of "lenses," screen frames or "films" for rendering your photo in, for example, sepia tones or other vintage flavors. Some, but not most, of these options cost extra - it's $1.99 for a "Fancy Lens Pack" that includes fish-eye, kaleidoscope and 3D formats.
Just for fun, there's Pocketbooth by Project Box, which is 99 cents on the iPhone App Store, $1.99 on Google Play.
The Pocketbooth app takes photos like an old-fashioned arcade photo booth, snapping off three or four color or black-and-white shots in a row and laying them out in a strip that you can post to Facebook and Twitter, send to a wireless printer, or have printed and snail-mailed for a couple of bucks. You can buy extra packages of photo effects.
Contact Reid Kanaley at 215-854-5114, firstname.lastname@example.org or @ReidKan on Twitter.