Cross-Platform USB File Manager

I need a lightweight application that sits directly on a USB flash drive and launches without installation, giving me straightforward file-management and organisation capabilities on both Windows and macOS. The core experience I’m after is the familiar ability to browse the drive’s contents, rename or delete items, create new folders, and drag-and-drop files within a clear, tidy interface. Nothing else matters as much as that day-to-day organisation flow.

Because I’ll be moving between machines frequently, the build must be genuinely cross-platform: a single executable for Windows and an equivalent app bundle for macOS, each pointing to the same data on the stick. If you prefer Electron, Qt, .NET (Win) plus Swift (macOS), or another portable toolkit, feel free to suggest what will deliver the snappiest launch-time and smallest footprint.

Deliverables
• Compiled Windows (.exe) and macOS (.app) versions that run fully from the USB drive
• Source code with clear, commented sections so future tweaks are easy
• A short read-me explaining any dependencies or code-signing steps

Once I can plug the drive into either operating system, open the program instantly, and manage files without extra installs, the job is complete.