WeVideo (limited in Free mode) (https://www.wevideo.com/) - haven't used it, but is a web based tool which provides a few interfaces depeding upon your skill levels. Supports layers.
Lightworks (free version): very feature rich tool. Supports layers and heaps more (https://www.lwks.com/)
VSDC: (http://www.videosoftdev.com/free-video-editor) - supports layers. Never used it, hadn't heard of it before today.
Look for editors that support layers.