ChimeIn is a cloud-based clicker application, developed by the College of Liberal Arts at the University of Minnesota.
The goals of ChimeIn are to provide both multiple-choice and full-text response clicker-style feedback without requiring dedicated hardware. ChimeIn leverages laptops, smartphones and "dumbphones" to aggregate responses.
A production instance is visible at https://chimein.cla.umn.edu/. We're working to develop a complete open source release, and would be interested in working with interested parties.
The ChimeIn code is licensed under the Apache license.