Air Chalk is a very interesting presentation tool for Mac. It displays a virtual black board on your Mac that you can write on using your iOS devices. Mac app acts as a server. You also need the Air Chalk client app installed on an iOS device.
When Air Chalk is running and you run the client app on your iOS device, and both devices are on the same network, the client version will be able to see the server and connect to it. When this happens, a full-screen blackboard will be displayed on your Mac's screen, and you will be able to draw on it by using your iOS device's touch screen. You can either draw with your fingers or input text using the iOS keyboard. There are many useful features like undo and redo, multi-color blackboards and eraser support, etc. I like the fact that you can replay what you have drawn or typed in your virtual blackboard after you have finished and that you can save your blackboards to PDF or image files.
This app is very easy to set up when both devices are in the same network. But it can also be used when there isn't a network to be connected to. This is the case when there isn't a wireless router that both apps can connect to. From the Preferences window, you can setup an ad hoc connection between the two devices so that they can still see each other.
In conclusion, Air Chalk is a very interesting app for presentations. It is easy to setup and it can be used in a variety of ways. You can even use two iOS devices if you don't want to use your Mac.
