Wick Editor doesn't require you to register or sign into any kind of account in order to use it. Simply head to the website and click "launch web editor" to get started. The editor itself doesn't have a lot of text or menus to tell you what exactly the features are or where they're found. You kind of have to just click and try things. That said, watching this tutorial video found on the Wick Editor homepage will show you everything you need to get started. I highly recommend taking five minutes to watch that tutorial video before using Wick Editor.
Once I watched the Wick Editor tutorial video Wick Editor was easy to use. I made a simple animation of a stick figure running across the screen. To make the animation I used the pencil tool and the onion-skinning tool in the editor. The pencil tool is exactly what you think it is, a pencil for drawing on the screen. The onion-skinning tool allows you to a slightly faded version of your previous frame while drawing on your new frame. That allows you to properly place your drawings in sequence so that they don't overlap unless you want them to. In short, onion-skinning in Wick Editor is like having a sketch pad open so that you can see your previous sketch on your left while creating your new sketch on the right.
When you're happy with your animation drawings you can tinker with the speed at which the frames are played back. After you've set the playback speed you can add audio if you want to include it. Finished animations can be saved as MP4 files or as GIF files.
Applications for Education
Wick Editor reminds me of a slightly more advanced version of Brush Ninja which I've used and recommended for years. Wick Editor, like Brush Ninja, could be used by students to create animations to illustrate science concepts. Here's an article that I published a few years ago describing the process that I used with eighth grade students to have them create animations illustrating forms of energy.