Server Density is a web service to easily monitor the statistics of your web-server. From their site,
Easy server monitoring
Monitor CPU load, memory, processes, disk usage, network traffic, Apache, MySQL & Nginx. Keep an eye on your servers and get e-mail, SMS & iPhone alerts when things go wrong.
Unlike most other server monitoring tools, Server Density monitors the statistics of your server and depending on the different watches/alerts configured, notifies you the same. For example, I have alerts configured for when my server load goes above 2.0, so I can take necessary actions even before the server becomes unresponsive and goes down. The statistics that the web-service collects is then presented in a nice, intuitive way on the web using dynamic graphs and a simple, yet elegant UI.
The service also has an iPhone app that, again, features a simple, yet elegant UI for your eyes. It was back in July that I wrote about the Server Density app on Smoking Apples. 5 months down the line, I’m still in love with the service and continue to use it with my servers. The app has been carefully and neatly crafted and there’s attention to minute details. The app also features subtle animations when logging in or fetching your server list.
With version 1.1, the app brought along statistical graphs, which can be simply viewed by turning the phone into landscape mode. The graphs presented in the app are so beautiful, I almost thought the design marvel at Tapbots was employed to paint it.
The app is available free in the App Store, but requires you to have paid account on the web-service to use it.