ut0ku/120fps-method ? reverse-engineered prompt

Build me a simple Windows desktop app that helps patch MP4 videos so they can be uploaded to TikTok without getting forced down to 30 FPS. I want a clean interface where I can drag and drop a video, pick a file another way if I want, choose where to save the patched version, and then click one button to process it.

The app should check that the input is an MP4 with a fixed 60 FPS or 120 FPS frame rate, then rewrite the video metadata only, not the actual video or audio data. After it finishes, show a clear success message. Please make it feel polished and easy to use, with the icons, translations, and basic branding included if possible.

If you need to look up current docs or best practices for the GUI toolkit, go ahead. I mainly want something that works reliably and looks like a real utility people could download and use.