Pairmotron was a SaaS app that psuedo-randomly selects pairs specifically for the idea of pair programming. I built this in collaboration with Mathew Bramson and others in the Elixir |> CLE group.
Pairmotron was written in Elixir with Phoenix, used Postgres, and was deployed to Heroku. Code is available on GitHub. Pairmotron was decommissioned in 2019.