Utils. Spare Parts (included), DiskUsage, ES File Explorer, Wifi Analyzer, Speed Test, ShootMe (a screengrab utility, root access required) and ASTRO, a file explorer with the ability to back up apps into .APK files.
Donovan Colbert has over 16 years of experience in the IT Industry. He's worked in help-desk, enterprise software support, systems administration and engineering, IT management, and is a regular contributor for TechRepublic. Currently, his professional role is as a Linux support engineer for a fast-growing Linux/FOSS consultancy group. You can follow him @dcolbert on Twitter or his personal blog, located at http://donovancolbert.blogspot.com.