If you are looking for a straightforward app to capture student thinking and understanding (audio and drawings), then you need to check out Doodlecast Pro (DCP). It's a great screen-drawing tool that incorporates voice recording and image imports. There are also many pre-set backgrounds to choose from (sports fields, graph paper, lined paper, music paper, etc.). We really like this app because it doesn't require an account - just install and go. The other great feature is that you can save your Doodlecast directly to the camera roll, upload to YouTube, or save to Google Drive.
There are many flexible settings for pen sizes, colours, and opacity. These can be changed mid-recording (the recording pauses while accessing the tool options). You can also add multiple pages to your recording. Many teachers use this app for running records - they take pictures of the text being read, and utilize the audio recording and pointer feature to record student reading. This is great for assessment and student feedback. The potential for this app is endless. It can be used across all grades and curriculum areas, and allows for differentiated assessment and instruction.
Teachers love this app because of it's ease of use and versatility.
Check out the introductory video below: