Stellar Survey offers free surveys that teachers and school administrators can use to get feedback about courses and instructors. Users can select from a predefined template and questions or create a survey from scratch. The free, basic account only allows 50 responses per survey so it is not ideal for large classes, but for most teachers 50 responses will adequate.
Applications for Education
Stellar Survey could be a good way to get anonymous feedback from students about the courses you teach. Stellar Survey could also be used to create a short quiz to use as a gauge of how much information your students are retaining.