I couldn't see the text guide in the app as shown in the Preview image of APPSTORE. It would be great if that info was accessible inside app when clicking help or something. The textedit file can be really helpful when trying to understand the speed of disk in mb/s and gb/s.
Still its a great app with a very similar interface just like Crystal Disk. I love it.
A powerful benchmarking app. The CrystalDiskMark for Mac, basically, if you are familiar with that piece of software for Windows OS.
Current app icon is not great all, though. But aesthetics aside—5 stars! Well done!