Adobe Premiere Clip brings free editing to Android
Adobe Premiere Clip arrived on iOS last year and now that app has come to Android. It's mainly a way to assemble your clips and photos, and it will create a video automatically. If you'd rather have more control over the result, you can load up all your content on your phone and then export it to the desktop version for more careful editing.
Here's a video about the 2.0 version of the app, which is the first version on Android.