I know Dynolicious on the Mac platform is supposed to be a great software for getting an HP/TQ approximation, but as far as actual datalogging, no idea. The most commonly used & liked (and cheapest) software is Torque/Torque Pro on the Android platform, with an ELM.327 bluetooth dongle for the OBD port. Easy to log to CSV file for analysis.
Forscan has just come out with their software for the iPad/iPhone (used to be Windows only), needs an OBD WiFi adapter (about $100 - couple of brands available) to work. I am still testing that with the OBDLink WiFi adapter, no comments on usability/logging yet. It has options to save as CSV/EMail a CSV file etc, though.