Janine, I have an Oscium iOS scope. It has one analog channel and four logic inputs. Being able to use your fingers to zoom in on a signal surely beats turning a knob. I have asked several scope makers if they would ever emulate that on their instruments. The answer is the same, "if there's demand, but people are so sued to their knobs."
Give it time.
The iMSO-104 works better on an iPad than an iPhone becuase of the bigger screen. I haven't tried it on an iPad mini.
Brian Dipert (along with Paul Rako) did a review of this over on EDN. Looks like a reasonable option for anyone whose applications are within its capabilities and who needs a portable solution, or just doesn't have room for a benchtop model.
Scopes, especially the mixed signal ones, are in a position to pick off some other test equipment commonly used. Anyone using a scope for an app today that they needed a specialized piece of test equipment for in the past?