Free ISO grabber is a wizard-based ISO creation tool. Since it makes use of wizards to guide the user through the process, Free ISO Grabber is able to keep the task easy and intuitive. There is a good amount of on-screen information to help new users understand the process.
The first few steps ask you which drive to read data from and what kind of interface to use. The interface will vary depending on your operating system. And they are listed on the screen for reference, so you can't get the interface wrong. Once the drive and the interface are selected, the application will start downloading the data from your drive into an ISO file. That is pretty much all the application does.
I didn't see any options to change the format of the image file, so I am taking it ISO is the only format supported, which would make sense. I also noticed there weren't any retry options for read errors, or anything of the sort. I always hope I don't need those, but it would be nice to have them.
In short, the app works well. It carries out a fairly simple task and it does it well. Speed-wise, Free ISO Grabber is only limited by the speed of your drive and your hard disk.