All themes published on Sufferless can be used for free but only with Sufferless hosting. You are not allowed to distribute, sell copies and download the themes or use it on other hosting.
You do not need to ask permission from or provide credit to the designer, developer or Sufferless, although it is appreciated when possible.
More precisely, Sufferless grants you an irrevocable, nonexclusive copyright license to use themes from Sufferless on Sufferless.co hosting for free, including for commercial purposes except distribute and sell copies of the theme or use it on other hosting except sufferless.co hosting, without permission from the designer, developer or Sufferless. This license does not include the right to compile themes from or by Sufferless or QDONOW to replicate a similar or competing service.