Port a .NET C# WinForm Application to MAC

Hey there Mac devs with a bit of Visual Studio C# experience who know and love AWS S3 I've got a quick one for you... We have a .NET C# winform app that we need ported over to Mac OX. Use Swift, Objective C, Coco, or whateves. I do not care as long as it works, its fast and I can mod it and freely distribute the app to my 4 or 5 internal users without additional cost. The Visual Studio project with full C# source will be provided -- so no stinkin' requirements gathering necessary. In short the app allows checks to see if there is an upload on launch and if so it patches and restarts. Then the user logs in. The user then selects a bunch of photos and adds the to a list. Then can preview individual photos when selecting and also when reviewing the list. Photos can be removed from the list or moved over to the "final" list. There is a go button to work the photos on the "final" list. When it's clicked the "final" listed photos are resized, some EXIF info pulled from each and then the resized images are transferred to AWS S3. When the transfer is completed and sound plays and the user is given the option to quit or continue. If the choose quit the app quits and their default browser is launched and directed to a specific url passed by the app. If the choose to continue the "final" list is cleared and they can repeat the process. Standard web services are used to validate the user credentials, log activity and record information about each photo. And of course there is a progress bar so the user know what's going on. This is a utility so it doesn't need to be pretty but it is used to transfer A LOT of photos and does need to be blazing fast. A bunch of effort has been put in to optimizing the S3 transfers using the multi-threading, chunk transfers, etc. Thanks for your time and I look forward to reviewing your bid. Dave