Host-tracker.com inspired me to make simple monitor for my websites.
Yeah, it's much more simple, feature-less. But let's hope not for a long.
It is basic rails3 app to manage websites, view responses, etc.
As a backend it uses loops. Inside loop it runs async checks with em-http-request.
Loops wasn't fully compatible with rails3, so I used fork of Yokujin that fixes generators. It wasn't enough - I commented out ActiveRecord::Base.allow_concurrency = true in lib/loops/engine.rb to make it work.