Skqueak is a neat iOS app that I learned about when Larry Ferlazzo nominated it as the Best Mobile App in the Edublog Awards. Skqueak makes it easy to enhance your pictures by adding your voice, drawings, and zoom effects to them. The app allows you to draw on your images in a Skitch-like way to point out important elements of the picture. You can also simply zoom-in on an element of your picture while you talk about it.
Applications for Education
Skqueak could be a neat way for students to create short digital stories about places they've visited, things they've done in your classroom, or about pictures that they've found online. You could use the app to add your voice to a chart or diagram that you're using in a lesson.