DDrillv7Lite is a Rig Floor Directional Drilling Survey app, which includes a survey data sheet, a Ouija Board and Percentage Drilling calculator.
It should be considered an introduction to the full version, which incorporates a proposal section and offset surveys section.
The DDrillv7Pro version facilitates interpolations, proximity analysis (no ellipse of uncertainty as yet), traveling cylinder plots, section and plan views, projections, ability to upload import data and email,download export files.