I’m not aware of any sites tracking our warrant canaries, but there are standards for machine-readable warrant canaries to make this easier

• https://github.com/firstlookmedia/autocanary
• https://canarytail.org/

Edit: oh, it looks like the EFF, Calyx Institute, Freedom of the Press Foundation, NYU Law, the Berkman Center, and a few other orgs run a service that monitors warrant canaries called Canary Watch

• https://canarywatch.org/

This update from 2016 says they were monitoring 70 org’s canaries

Edit 2: oh, looks like they silently shut it down some years ago :( well, we adopted the autocanary standard from FLM linked-above, so it shouldn’t be hard for some canary observatory to consume and track our canaries.