RetopoFlow includes a full suite of retopology tools, designed for a variety of tasks and scenarios such that you can tackle most any retopology project with ease.
The tool you use for each task depends both on preference and need. For example, if you’re retopologizing a character’s arm, then you’ll likely want to use the Contours tool. On the other hand, if you’re retopologizing a rock for a game asset, then you’ll likely want to use the Polypen tool for it’s ability to create triangles.
Some tools are only available in Edit Mode, while others work in both Edit Mode and Object mode. See each tool page for details.