What the Air Sketch app allows you to do is to turn your iPad device into a virtual whiteboard. The app is extremely easy to use and apparently intuitive which cuts back on you having to spend time on trying to figure out how it works.
The best feature about this is that it is wireless. Basically, it means that you can connect your iPad device wirelessly to a variety of devices including a projector. It means that you can use the device to demonstrate things to a classroom while moving about the room. Now I have taught in rooms with a computer hooked up to the interactive whiteboard. I used to sit at the computer and we would put notes up on the screen or I would stand in front of the board and use a stylus. However, the idea is that with the Air Sketch I can wander about the room and use it while teaching. Or the students could use it show their ideas to the class. Now I do know that some interactive whiteboards come with wireless tablets that do the same thing. This is for those teachers who only have an iPad and an interactive whiteboard.
Before you buy it, check that it will work on your school network. One of the requirements is that it requires a browser running HTML5, which is basically what we would call a modern browser like, Chrome, Firefox or Safari. If your school uses Internet Explorer there is a chance it is an old version and might not work. If you aren’t familiar with this type of technology check with the local IT staff. I’m sure they will be more than happy to help you out.