Easy Packet Blast

Easy Packet Blast is a fast and free application to send one or many (UDP) packets to a single destination address. You can select the port and destination, as well as give a custom payload for the packet. This is useful for network testing, load testing, hardware testing, etc.

You can download it from the Android Market here.

Update 4/2012 This is now open source and hosted on GitHub. Check it out at my GitHub page.