SignBridge

Inspiration

I was inspired by my experience working with Muskaan NGO, where I got to spend time around Deaf and specially abled learners. I noticed that many learning tools are not really made for them. A lot of tools treat their writing like normal grammar mistakes, but for many Deaf learners, sign language is their first language and written English is a second language.

That made me think: what if AI could help bridge the gap between sign-language thinking and written English in a simple, visual, and respectful way?

What it does

SignBridge is an AI literacy platform for Deaf and sign-first learners.

A learner can write a sentence in their own natural way, like:

Store I go yesterday.

SignBridge then helps them understand how that idea becomes written English:

I went to the store yesterday.

It does this using visual concept cards, simple lessons, guided practice, hints, reading practice, fingerspelling, accessibility settings, offline lessons, and a teacher view for progress.

How I built it

I built SignBridge as a full-stack web app. The frontend is a React PWA, so it can work like an installable app and also support offline fallback lessons. The backend is an Express API that talks to Gemini for AI responses.

The app uses structured AI responses so the lesson comes back in a clear format: corrected sentence, skill focus, explanation, concept cards, practice, and feedback. For fingerspelling, it uses on-device hand tracking, so the camera video does not need to be uploaded.

Challenges I faced

The hardest part was making the AI feel useful without making it confusing. I did not want the app to just say “this is wrong.” I wanted it to explain one thing at a time and make the language change visible.

Another challenge was making the app reliable. AI APIs can be slow or rate-limited, so I added reviewed offline lessons as a fallback. That way the learner still gets practice even when the live AI is unavailable.

What I learned

I learned that accessibility is not just a feature you add at the end. It has to shape the whole product. I also learned how important it is to build with empathy, especially when the users may not learn in the same way most apps expect.

What makes it different

SignBridge is not just a grammar checker. It is built around the idea that Deaf learners are crossing between two language systems. The app respects that and teaches through visual meaning, practice, and progress instead of only correcting mistakes.

Built With

• api
• app
• css
• express.js
• gemini
• google
• html
• javascript
• mediapipe
• node.js
• progressive
• react
• render
• tailwind
• tasks
• vercel
• vision
• vite
• web
• workbox