qgSurf is a field-mapping/structural-geology plugin that can be used as an aid in: a) estimating the attitude of sub-planar geological surfaces given three or more points on a topographic surface; b) determining the intersection between a geological plane and a topographic surface; c) calculating the distance between points and a geological plane; d) plotting geological data in a stereonet; e) creating geological profiles.

GitLab Repository
QGIS Python plugin repository