RetopoFlow is an add-on for Blender that Jonathan Denning, Patrick Moore, and myself have been building over the last two years. Originally it was just the Contours tool, then Polystrips. Now those two tools are being combined into the single RetopoFlow add-on, which will be released soon on the Blender Market.
In most cases, retopology is a tedious, cumbersome process that most people loathe (although I have a strange love for it). It generally involves a lot of manual work, and no small amount of skill/practice to get good edge flow.
The purpose of RetopoFlow is to ease the whole retopology process, by creating an advanced, artist-friendly retopology workflow that's fast, flexible, and easy.
Here is a small teaser of some of the updates that're coming to Contours and Polystrips in the first release of RetopoFlow:
Add-ons like this are very complex, but we've worked really hard to make it simple, intuitive, and powerful. We've made a lot of progress since the first releases, but there's always more work to do.
I'll be using this forum thread as a development log of sorts, posting updates and sharing insight into our development process.
If you have any questions then please ask away! Feel free to share feedback as well, particularly if you've used the currently available versions of Contours or Polystrips.
Note: I'll also be updating this first process with details on the latest version as it becomes available.