Tabbycat is an open-source project developed by volunteers, and is free to use for tabbing non-profit, non-fundraising tournaments. Donations to Tabbycat from individuals or organisations are much appreciated.
Using a real debating app makes speaking and adjudicating easier! Check out Timekept (iPhone/iPad) or Debatekeeper (Android).
Use debatingBallot.com to design and print great ballots online.