Price: free Download on the App Store
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 iPhone app, may not even come up with comparable results.
So why, then, would you even use an app like Speedtest.net? The value is running your test and comparing your results over time. You can learn, for example, what time of day your network is fastest. If your network seems slower or speedier than usual, you can run a test to verify whether that's true or if there's something else going on.
Recently, I've tried a couple of these apps — Oookla's Speedtest.net and xTreme Labs Speed Test — on my iPhone over Wi-Fi and EDGE. I've yet to get comparable results between them. Both are free; but Xtreme's app is ad-supported. I decided to stick with Speedtest.net as my app of choice because it's ad-free and has a much prettier interface.
At the end of each speed test, these apps display download (the speed of data from the server to your computer) and upload (the speed of data from your computer to the server) bandwidth speeds.
The Speedtest.net app automatically runs its test against the nearest Ookla server in your area (in my case, that's Nashua. N.H.). On a midday Sunday, iPhone speeds over Wi-Fi were 2995 kilobits per second (kbps) and upload speed was 1235 kbps. My EDGE speeds were 42 kbps download and 9 kbps upload. The results for both were significantly lower than I usually see.
For the sake of comparison, I also ran Xtreme and the results were nearly twice those of Ookla's app. Like I said, there are many ways to explain the differences.
The point is, choose on app and stick with it and compare your results over time. By the way, you can test your desktop speeds at Speedtest.net, Ookla's Web site.