Know Recorder is a free iPad app and free Android app for creating whiteboard-style instructional videos. With Know Recorder installed on your iPad or Android device you can draw and talk while the app records everything that you do and say. Your video can have multiple pages which is a nice feature when you want to give a multiple step demonstration without having to erase anything. Know Recorder will let you import PDFs and pictures to display and annotate on screen in your instructional video. Completed videos can be saved to your device's camera roll, exported to YouTube, or shared to Know Lounge. Know Lounge is the community site for sharing lessons created with Know Recorder.
Applications for Education
Of the all of the free apps that offer this service, Know Recorder is probably the best overall for teachers. With this app you can create all kinds of instructional videos. You could use it to create a math lesson, use it to create a science lesson in which you're explaining parts of a diagram or illustration, you could also use to show students how to analyze text.