System Manager for iPhone is an inexpensive app that provides information about your device’s use that you can’t get in any native application—specific information about memory use, disk space, battery life, and device identification.
iPhone and iPad apps tagged "performance tests."
Speedtest.net: Need for Speed is Relative When Network Testing
When it comes to bandwidth network speed testing apps like Ookla's Speedtest.net everything is relative. The results you get depend on your distance from the server you're running the test against, the number of people within proximity who are accessing the same network, your service provider and other variables. Two people, standing within feet of each other, running the same app, may not even come up with comparable results.
iNetwork Speed Test for Network Nutters
Are you a network nut? You know, a person who constantly wonders how fast his or her network connections are? Do you have bookmarked two or three sites where you regularly go to check your bandwidth?