What the app does is a mystery when using it
There's no way to tell what the app is doing when you press a button. You'd think that "delete gapps" means it searches for specific package names from a database and uninstalls the apps, but it actually uninstalls anything that has "google" in their package name, and can't even uninstall /system apps completely. It basically fails at what you wanted it to do, and succeeds in uninstalling apps that you wanted to keep on your phone, including Ungoogled Chromium.
I suggest that you add a confirmation dialog that shows up right before uninstalling any apps with their names listed or a menu where the user can pick the apps they want uninstalled.