Hi DEV! I recently shipped NeoDark Pro, the premium version of NeoDark (a free dark-mode WordPress theme for tech guides and reviews), and the more interesting part of that launch wasn't the theme itself — it was adding proper license-key licensing to it without touching the original codebase or the free theme at all.
The setup
NeoDark Pro adds a homepage hero slider, dedicated review content blocks (Quick Facts, Pros & Cons, Comparison Tables, Verdict Boxes), a mega menu, full-width landing page templates, and a built-in download counter on top of everything the free theme already does. It had been selling as a plain WooCommerce downloadable product — pay, get a zip, done. Which meant: no license enforcement, no update delivery, and the raw zip could be shared indefinitely with nothing checking whether the person installing it had actually paid for it.
Why not just bolt it onto the existing package
The free NeoDark theme is in the WordPress.org Theme Directory review queue, and the Pro package was already a sold, working product. I didn't want to risk either of those by editing in place. So instead of modifying the live Pro codebase, I built a fully isolated copy — same theme, plus the Freemius PHP SDK dropped into vendor/freemius/, plus the SDK's init snippet added to functions.php, plus the readme.txt format Freemius expects. Nothing about the original free theme or the previously-sold package changed at all; the licensed build is a separate artifact that happens to start from the same source.
