With very little effort you can find a dozen photo apps on the Mac App Store which perform one or two tricks, and nothing more. PicFrame is a good example. This 99-cent app lets you create photos with frames, collage style.
Select the frame you want from the sidebar, then drop photos into PicFrame.
Select a frame that holds up to nine photos. Zoom and drag the photos within the frame to obtain the desired composition.
Then, use to pop down tool window to adjust the frames.
Frame corners are easily rounded and adjusted with the slider bar. Frames can be slimmed or enlarged, color can be changed, or simply click to add a pattern to the frame.
The frames hand ratios from 1:1 all the way to 16:9, and high resolution photos up to 3264 pixels, but not standard size frames such as 11×14 or 8×10.
What’s missing? What you get is useful for 99-cents, but having some way to rotate photos within a frame would be a plus.
Still, PicFrame does what it does quite well, and very quickly. It just doesn’t do more than 99-cents worth.