The user interface of Visual Studio (user experience) at MacBook version is not as good as the windows version. So, I did all the development at Windows (visual studio). ok, time to test the app. I got an iPhone and MacBook (both 2nd hand purchased at eBay, ok that's not important here). start deploy... it says enable remote login.. ok.. done... continue deploy and this time.... Mono is not install at the MacBook... ok... installed Mono start deploy again.... this time.... Xamarin.iOS SDK cound not be found... alright... install Xamarin.iOS.... and.... require XCode... alright ... find and get XCode... and.... require MacOS 10.13.6 alright ... go ahead and download MacOS 10.13.6... .... ok... downloading... MacOS 10.13.6 now... anything else? perhaps yes, lets wait and see...