Clips is an iOS app, so iPhone or iPad, that allows you to easily create a video with features similar to what you can do in Instagram or Snapchat.  You can create a quick video and add over symbols, animations, text, filters, and other options. 

The key feature that makes this app stand out to me is the Live Titles option.  By turning on the Live Titles option, you will enable it to transcribe your audio into words that will appear on your screen.  You can go in later and fix those words if they are not correctly transcribed.  You even have some options on the appearance of the text.  

This will make the video that you, or your students, create much more accessible to anyone who may have a hearing issue or who is not a native speaker of your language.  Just by doing the simple task of correcting the transcribed words, you greatly improve the accessibility of your video.  Again, the words may not show up 100% exactly correct but it is so easy to fix those words that you should not let that stop you from creating very accessible videos.