MultiMC/Launcher ? reverse-engineered prompt

Build me a simple desktop launcher for Minecraft that lets me manage multiple separate game installations in one place. I want to be able to create, switch between, and launch different Minecraft setups without them interfering with each other, so it stays predictable and easy to use.

Keep it focused on stability and simplicity rather than flashy extras. Make the interface clean and straightforward, with basic controls for adding instances, selecting versions, and launching the game. If there are account sign in or online service pieces needed, use the current docs and best practices for those, and look up anything current online if you need to.

I’d also like the app to feel polished enough for everyday use, with sensible defaults and no confusing setup. Please build it so it can be customized and branded as its own launcher, not tied to any existing name or logo.