Poll Everywhere makes it extremely easy to create and display polls. The interface is clean, navigation intuitive, and instructions easy to understand. I have used it both as an adjunct professor and as a marketer. Despite having different demographics in both instances, both groups of people were able to easily submit their answers via text message or internet browser.
I love that there is a free subscription for educators (and students). As of writing this in May 2018, users can collect up to 40 answers with the free version, which works perfectly for me since my class sizes are ~20 students. My students have also commented that it's a nice feature to have during lecture as it helps keep them focused in an engaging way.
There are various polls you can choose from -- multiple choice, Q&A, Word Cloud, Rank Order, Survey, Clickable Image, etc. In the two years I have been using Poll Everywhere, they have doubled the types of polls you can choose from and create, demonstrating PollEv's attention to growth and innovation. You can also group and categorize poll questions, which has worked perfectly for me as it's allowed me to group poll questions according to the day and lecture.
Another great feature? PollEv's integration with PowerPoint. The integration is easy to download and use, and it allows me to seamlessly embed polls into my PowerPoint. This way, I don't have to leave the PowerPoint and pull up my internet browser. Review collected by and hosted on G2.com.