More likely to have a problem with specific distros (because of the different methods especially the Live iso's use for loading). For example, I never had any success with openSuse using Unetbootin but could easily create a bootable USB from within another Linux whereas e.g. Ubuntu worked fine using Unetbootin.
Have also seen reports of cheap (unbranded type cheap) USB sticks not working too well but can't comment first hand.
As for using the app, couldn't be easier: plug in the thumb drive, fire up the app, choose the iso file, (check it is pointing to the right USB device - obviously), click go. The manual (or help files) aren't that complex
One other thing you might notice when you come to re-format the USB stick in Win, is that it appears only to be the size of the iso regardless of it's real capacity. You may need to do format twice to "restore" proper capacity.