Screenr is a simple to use, web-based presentation tool that allows you to capture computer screenshots and audio together to create short videos.
I can see many uses for screenr in the classroom. A teacher could put together a screenr video about how to do just about anything on the computer, from correct internet research techniques to working in Excel. Then, the teacher could publish those videos and give the links to his/her students. That way, students could view the video as many times as they needed to in order to understand the material being presented. The teacher could even create a collection of tutorial videos for different software that students could access only when they needed help using the program; therefore, the teacher wouldn't have to waste valuable class time giving lessons about programs that some students already knew how to use and others weren't planning to use at all.
Students could also be expected to use screenr. For example, the teacher could assign groups of students to make each of the tutorial videos described above. Or, if students were expected to make a presentation about a topic, they could create a screenr instead of doing a live presentation in front of the class. The teacher could also use it as an assessment tool, asking the students to demonstrate their mastery of a certain tech skill by creating a screenr rather than having to spend class time watching every student show that they understand.