Years later, I'm making good on that promise: introducing License Detector (https://licensedetector.com) -- a license detection tool that works across 21 ecosystems, basically every major language, and it's free in the web app for any open/public repo!
I'm also releasing the CLI for free as well (https://github.com/licensedetector/cli), so you can run it on your own repo before installing anything. The tool is ~80x faster than licensee, and matches or beats askalono and scancode-toolkit on accuracy in head-to-head benchmarks (I've included the benchmarks as well in the repo if you wish to run them yourself).
Hope people try it out and enjoy it, and would be glad to answer any questions!
CLI: go install go.licensedetector.com/cmd/license-detector@latest
GitHub App: https://github.com/apps/license-detector
Benchmarks & how it works: https://licensedetector.com/compare#how-we-stack-up