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.
OpenStartup.dev - A collection of open startups
SurveyJS - Feature rich and open source surveys for embedding into websites.
Plezi - Plezi offers content marketing management software solution.
Votee - Easy, reliable, and cost effective market research
Viable Fit - Measure and improve your product market fit