Internet Speed Test App allows you to get accurate download and upload speed tested of your network with detail report of all the testes performed. It has a unique algorithm that cannot be tricked by PowerBoost or similar speed enhancement tools, so the results you achieve will be accurate per your system data speed. Internet Speed Test is a single-threaded test, while most others (like speed test dot net) are multi-threaded. It uses a single connection to download the sample files, which is closer to what you actually do in your everyday browsing and downloading
Note: The downloadable demo is version 3.0; the version available for purchase on the Mac App Store is version 3.3.