Netumo monitors your servers (like websites etc.) and checks it's content based on a frequency you set. As soon as something happens you get immediately notified via Email/SMS/Twitter.
Netumo keeps a list of all your domains from different registrars in a single location. When any domain is due for expiry you get notified.
Netumo stores all the ping data and presents to you reports so that you can easily spot trends, on your server load and website health.