I'm learning Mexican Spanish and built Spanish Buddy, a web app with a personalized daily curriculum to reinforce what I'm learning. I found that most Spanish apps and resources default to European Spanish, which misses vocabulary, slang, and pronunciation that matter in Mexico.

I built the whole thing with Claude, mostly in Cowork. I started by prompting Claude to build an entire 12 week curriculum based on my individual learning goals and then broke that down into interactive daily lesson apps (React components), spaced-repetition flashcards, dialogue and listening exercises, and progress/mastery tracking. With the content generated, I turned to Claude Design for the branding and UI components. Cowork also walked me through the use of MS Azure to create a pre-generated Mexican Spanish audio pipeline so pronunciation is authentic instead of robotic browser text-to-speech, and finally how to use GitHub and how to deploy the site itself.

Some interesting stats from the build:

**- 84** daily lessons, spanning the full 12-week curriculum  
**- 130,800 lines** of code (roughly 652,000 words, 5.7M characters of source)  
\- The curriculum spec doc alone runs **14,806 words / 1,852 lines**  
**- 5,606** individually generated Mexican Spanish audio clips

It's completely free to use at [spanishbuddy.app](http://spanishbuddy.app/), no signups or downloads or paywalls. Got my first supporter today, which felt like a nice milestone for something that started as a personal fix for my own learning gap.

Currently using it every other day and it's made a real difference over the generic apps I tried before!

My app made its first dollar 🥳