Pixel Toolbox is an easy to use application for creating and designing pixelated characters.

When inspiration hits, open the app.
Create a character folder.
Create an action sequence folder for the character.
Create the first sprite frame for the action sequence.
Copy the frame and adjust movement changes per new frame.
After having created some action frames, you can use the frame slider option to view the frames in a controlled animated way.
Reorder the frames with a simple longpress and drag it to a new position.

Export the action sequence as a spritesheet frame with only the action sequence itself. Or when you have multiple action sequences, export it as a spritesheet with multiple rows (one row per action sequence).
The exported sprites can also be scaled to a bigger format.