Have a look at bping http://gizmoware.net/bping/ you don't even have to keep an eye on it, you can set it to one of two settings, sound on error or sound on resolve. So if you have a server that is always on, you can set it to beep when the server goes off, or you can set it to make a sound when the device comes back online. I have it on hand when I am restarting things and don't have to "watch" for it to come... Source: almost 2 years ago

All the code for my app is in the repo (https://github.com/nedrysoft/pingnoo). My application is built in a module fashion with plugins (I call them components). The plugin system and theme libraries are in src/libs. Source: about 3 years ago

I specifically list both the open-source and commercial products I use, some of the commercial tools are invaluable to me and often they are bargains for what they offer, even more so when they go on offer. (https://github.com/nedrysoft/pingnoo/#readme). Source: about 3 years ago