MyIPConfig - This program displays your current IP Configurtion, Subnet Mask, and other useful Info
NBStatCE - This program allows you to see various devices on your local network
Ping - This is a dialogue box version of the command line Ping command
Pocket Ping - This is a somewhat more advanced version of the same concept, with definable intervals for pinging, and Local Host info
WiFiFile Sender - I've also included this wonderful program, which makes sending programs over the network MUCH easier, even if the files are very large! The author has also made PC and Android versions, which can all communicate with each other.
(Disclaimer: All programs are the property of their respective owners, I have merely collected them for your convenience)