Educreations Interactive Whiteboard is a tool that students and teachers can use to create lessons using images, text, drawing, and voice. It is a free app that is easy to use, and allows you to record yourself writing and speaking. It may be most useful for teachers who want to make tutorials for subjects such as math that students can follow along at home. It is easy to use, however an account is needed to make tutorials, but a Google Account can be used. You are able to add photos to draw on as well as pause and play recording, allowing the user to make more complicated tutorials.
The interface is intuitive and has a decent amount of functionality. Different backgrounds are available with white, lined, and graph paper, with or without a grid. Two fingers can be used to scroll down for more room, and multiple slides are available for use.
Some examples of lessons recorded (no voiceover) can be seen below: