4* - because nothing is perfect, and there is always scope for improvement.
This is a very useful app, which is straight-forward to use, so I gave a donation, which I encourage others to do also; it's nice to be nice and show ones appreciation.
The app disappeared from my browser recently, and when I re-installed it I was no longer on a "Pro" standing, which limited my use, so I contacted the developer, and the next morning there was an email from him/her with the fix!
