Best Platform to post "Conversation Practice" files for GEPT study.

I’m holding practice sessions for GEPT study. I’ve found that to keep the students honest, recording is a great feed back tool. My only problem is how can I deliver the results for them to listen to and perhaps submit improvements.

Right now, I’m experimenting with a private facebook group. I convert the audio to video. If the kids choose, they could cover the camera if they wish and submit an improvement.
** Annoying fact is Facebook posts later videos on top. To put the session in proper chronological order, I will just have to post the videos in reverse order.
Is there an other platform that would be easier to use? Perhaps Youtube?
I need something that is easy and flexible. As most of my students their parents have Facebook, I guess this would be the best choice. I also like the ability to communicate with the students with out them being actual Facebook friends. We are old fashioned and don’t believe that students and teachers should not share friendships.

I wish there would be a platform where I can easily control the permissions. My wife and I really don’t want our daughter to have Facebook actually. Not that my daughter needs much listening practice, we will only let her access Facebook through my machine, unless there is a Facebook parental control feature out there. It doesn’t seem to be an issue with other parents but, it should be.