What's the best tool you found already sitting inside something you were already paying for?

Higgsfield's OAuth login has been stuck for three days straight. Every blog post I published this week shipped with stock Pexels photos instead of the illustrations I actually wanted.

Out of options, I tried Codex CLI's built-in image_gen tool, the thing I use daily for actual coding and had never touched for images. Turned out it was already signed in via my ChatGPT auth. First prompt: two on-brand illustrations, 1672x941px, matching my style guide, zero watermark issues, on the first try.

What's the equivalent for you, a real capability you were already paying for, sitting unused until something else broke?