Yes, Microsoft offers a number of tools and platforms that you can use to develop a mobile app that allows your users to upload files to your server using anywhere access.
One option is to use Microsoft's Visual Studio App Center. This is a cloud-based platform that allows you to build, test, and monitor mobile apps for iOS, Android, and Windows. You can use the App Center API to build custom integrations with your server and allow users to upload files.
Another option is to use Microsoft PowerApps. This is a cloud-based platform that allows you to build custom business apps without writing any code. You can use PowerApps to create a mobile app that connects to your server and allows users to upload files.
Both Visual Studio App Center and PowerApps offer a number of pre-built connectors and templates that you can use to build your app quickly and easily. They also offer robust documentation and support resources to help you get started
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