Polls - polls support a feature that lets users add their own answers rather than selecting an answer from a preset list. The poll creator can view these answers in the statistics report and decide if they would like to add them to the poll (the answers are not auto-added to avoid duplicates/typos/etc). In addition, you can also integrate a lead form in the poll which can include any number of open-ended fields.

Forms / Surveys - support two types of open-ended questions - "short answer" & "long answer". You can use these questions anywhere in your survey. In addition, you can also integrate a lead form just before the last screen of the survey that can include any number of open-ended fields.

Trivia & Personality Quizzes - you can integrate a lead form just before the last screen of the quiz that can include any number of open-ended questions.