Many students record lectures to revisit later. In fact, recording learning material allows some students to be competitive with the learning styles of their peers.
However, navigating long recordings can be daunting, and these huge files can take up lots of space on a device. For this, Cogi is a great alternative -- this app allows you to easily start and stop when you want to record something, instead of recording the entire lecture. It's low bandwidth and small in size, and also easy to navigate.