Survey Monkey - Create and publish online surveys in minutes, and view results graphically and in real time. SurveyMonkey provides free online questionnaire and survey software.
Product Market Fit Toolkit - Measure your product-market fit using data you already have
SurveyJS - Feature rich and open source surveys for embedding into websites.
Viable Fit - Measure and improve your product market fit
Votee - Easy, reliable, and cost effective market research
FaqFox - Find the questions your target audience is talking about