Note: The NtK Model for Freeware contains Stages, Steps and Gates that may vary across the five sub-categories, as described in the five columns below.

Freeware Fee App Freemium/>$5 Free  DIY Fee DIY/Training
  Obtain a freedom to operate certificate via a patent attorney as a minimum precaution Obtain a freedom to operate certificate via a patent attorney as a minimum precaution   Obtain a freedom to operate certificate via a patent attorney as a minimum precaution