This article, Every Student Should Be Given the Opportunity to Teach Others, presents excellent reasons for students being able to teach. Thinking back to my own learning experiences, I best remember the lessons I was taught when I was able to present/teach others.
Platforms for Students Teaching Students
Screen-castingScreencastify - There are limited features in the free version, but there is enough to successfully create and present a screen-cast.
VideosRecord and post videos through Google Drive or YouTube. The app ShowMe, for tablets can also be a good way to create a presentation while explaining concepts.
An interesting concept that you might want to try is using the Vine video time limit in having students create videos. The time limit really makes the student think about what is most important. Check out this resource. 3 Ways to Use Vine in the Classroom.