Currently we do not have an official Desktop Application available.
However, we do support third-party clients such as shareX running version 9.x or later.
You can find a step-by-step guide for ShareX 9.3.x at: http://uploadme.me/page/sharex-step-by-step
Currently UploadMe only supports uploading images as a guest. All uploads via our API will appear on the CoreAPI account. In the future we plan to release our own Windows and Mac clients with account support.