Whatsup.status.io

We published a service for checking the current status of an API: http://whatsup.status.io

4 distributed nodes are monitoring the service availability of each API by inspecting the endpoint's HTTP response and/or performing synthetic transactions, latter being the goal for all checks.

We are already using this for another project and thought others may be able to benefit from it. Does anyone else find this tool useful? How should it be improved?