From Ookla Net Metrics:
Speedtest.net Speed Test for iPhone measures the performance of your broadband connection. At the end of each test, you are presented with the download (the speed of data from the server to your iPhone) and upload (the speed of sending data from your iPhone to the server) bandwidth speeds. Speed Test saves your scores with dates so you can track where you get the best connection speeds.
What's new in this version:
Version 1.5.1 includes location identification improvements, and fixes.