What I Built

"Sweety, how do you do this?"

"Sweety, how do I video call?"

"Sweety, how do I forward this message?"

That's my Nana. She loves WhatsApp. WhatsApp does not love her back. And every time she gets stuck, I get a call.

A little context: I'm job hunting right now, and I've been wanting to start contributing to open source. While looking around, I rediscovered Hacktoberfest and found this challenge with only about 2-3 hours in my hand before the deadline. I had just hung up from my usual night call with Nana, so I didn't have to think too hard about who to build for.

So I built her a helper: Nana, Press the Green Button.

It's one simple page with big buttons. Video call, send a photo, voice message, forward a message, bigger letters, block spam. She taps what she wants and gets five short steps that tell her exactly what to press, in English, Hindi or Marathi. It describes buttons the way she sees them, like "tap the small camera at the top" instead of "navigate to the video icon."

It also warns her if she ever asks about OTPs or bank details. Because scammers have her number too.

She can open it on her phone and keep it on her home screen like an app. Now she still calls me, but at least it's to say hi.

Code

Malisha27 / nana-green-button

A big-button WhatsApp helper for grandparents, powered by Gemma. Hacktoberfest 2026.

🟢 Nana, Press the Green Button

A tiny WhatsApp helper for my grandparents. Big buttons, simple steps, English / Hindi / Marathi Powered by Google's open-weight Gemma 4 model via the free Gemini API.

Built for the DEV Hacktoberfest Weekend Challenge: Build for a Friend (Oct 2026).

Run it

Get a free API key at https://aistudio.google.com/apikey
Install and run:

pip install -r requirements.txt
$env:GEMINI_API_KEY="your-key-here"      # Mac/Linux: export GEMINI_API_KEY="your-key-here"
streamlit run app.py --server.address 0.0.0.0

On the laptop: open http://localhost:8501

On a phone (same WiFi): open http://<laptop-ip>:8501. Find the IP with ipconfig (Windows, "IPv4 Address"). Add it to the home screen so it opens like an app.

How it works

WHATSAPP_NOTES in app.py is a hand-written cheat sheet of WhatsApp steps.
Gemma is told to answer only from those notes, in max 5 steps, in the chosen language, describing buttons by…

View on GitHub

How I Built It

Gemma 4, Google's open-weight model, through the Gemini API

Streamlit for the app, styled to feel like WhatsApp so it doesn't scare her

A small cheat sheet of correct WhatsApp steps that I wrote myself. Gemma only answers from it. If she asks something that isn't covered, it says "Please ask your grandchild to show you this one" instead of guessing. A wrong step is worse than no step.

I actually started by running a smaller Gemma model fully offline on my laptop. It worked, but the first answer took over two minutes. Nana does not wait two minutes for anything. Since Gemma is open, switching to the hosted version took a couple of lines, with the same model family and the same prompt.

Why Does Open Innovation Matter?

Because I'm not stuck with one way of running it. Tonight it runs on Google's API. On a faster laptop, it can run completely at home, so Nana's questions never leave the house. That choice only exists because the model is open.

It's also free, and if her Marathi answers need work, I can switch model sizes or fine-tune it for her myself.

Building for one real person made every decision easy: bigger buttons, fewer words, her language, no made-up answers.

Nana, Press the Green Button (a Whatsapp Helper)