Wooclap

Question1: List all options but differentiate present/absent (e.g., green/red -- but better colorblind alternative; like first option)? OR only list the present options (like second version)?
Question2: Just list the options (like first version) or make them links to collection of all those that have the option (like second version)?
Rights: GDPRno registrationopen sourcerecommendedsufficiently freeTUM
Rights:

Voting/survey/quiz tool. Broad range of question types (including SCT and point-within-picture), with real-time reporting. Maximum 1000 participants. Can integrate with LMSs, use SSO. Podium function for high scores.

Commercial provider, very limited base version, teacher registration required (students can answer anonymously, or with SSO). Since 2015.

2 questions, 1000 participants
€84/year
Unlimited questions, user paced questionnaires, presence list, data export.