We have two types of open-ended question polls:
Short answer: Participants can respond with up to 100 characters. If it's a live presentation, the responses are displayed on screen in the order received and cycle through.
Wordcloud: Participants respond with one or more words. The responses are then displayed as a "wordcloud" with the more frequently occurring responses appearing larger.
An alternative approach that may also be useful in some situations is to use the "Activity" section. Activity is essentially a comments section where participants can post as many comments as they like of whatever length they like. Similar to social media, each comment can be "liked" by other participants and you can then sort all the comments by "most likes". You could therefore ask your participants to share their responses in the Activity section and to also "like" any comments they agree with.