Our school has Windows based devices. In the past we have used Microsoft's free software Photostory and Movie Maker Live with students to create videos. Unfortunately Microsoft has discontinued both and replaced them with their new Windows 10 Photos App.
It took me some time to make the switch but I am happy to report that I don't hate it. There are some things I would change but overall it is fairly easy for students to grasp. I like the effects and 3D options and for short videos it is an adequate (and free) app. The video summary above of "Harry the Dirty Dog" will highlight what students can do.
I always liked the time before a holiday break to introduce students to a new tool. It helps to set them up to use the tool independently with future projects.
If you want to try this with students I would recommend making a project yourself so you are familiar with how the tools work.
My suggestion is to introduce a short holiday read aloud and have students work in groups, or it can be done whole group as well, to summarize it in seven sentences (I also impose a word limit of 5-10 words for each sentence). Once they are done they have to find seven pictures online to represent the sentences (which is what we did with the Harry the Dirty Dog example above).
Then walk students through the creation process from adding captions, changing timing, using a theme, using audio, and of course the creative use of those effects and 3D elements.