The Retopo MT addon allows you to retopo a mesh by drawing lines. The first line creates a row of faces. Then you can draw another line on one of the sides and you have your second row of faces. It works a bit more sophisticated that only Bsurfaces.
It seems that the addon was originally written by Pitiwazou in January 2015 and is ported over now by cwolf3d to Blender 2.8. Anyway, I got it to work within a minute or two and couldn’t wait to post is here on blender-addons.org, telling you the great news.
How the Retopo MT Addon works
To give you the very basics, you need two objects. Start with a monkey and a plane. Select the plane and go in edit mode. Then press X, delete all vertices. Press Shift+Ctrl+Alt+X and draw a line on Suzanne. This will create a row of connected faces. Draw another line on one side of the row to create another row of faces. Be sure to draw close enough to the first row.
If you have a few faces and the faces are not connected, you can also draw a line from one face to the other. Start drawing in the middle of the first face and end in the middle of the second face. Press W to generate more faces and X to reduce the amount of faces. With this method you can create and connect other faces as well. There are other methods but so far I can’t get them to work because pressing the space-bar will start the timeline. Let me know if you experience the same issue or not.
Where to download the Retopo MT addon?
You can download the Retopo MT addon on Gumroad. And for more information check the thread on BlenderArtists.org. The addon is free but you can consider to name a price. The developer will be happy with anything.
Installing the addon is as usual; In Blender go to Edit > Preferences > Addons > Install. Navigate to the .zip file you just downloaded and press Install. Activate, save preferences and refresh. You enter the addon by pressing Shift+Ctrl+Alt+X.