How I Built a Full-Stack Android App at 84 Years Old (Using Google Gemini as my Junior Dev

Source: Dev.to

Background

They say you can’t teach an old dog new tricks. I firmly disagree.
I started my career as a British Telecom apprentice in 1960, spent decades managing technology projects across Africa and Asia, and developed patent‑winning security systems for De La Rue. I know engineering, logic, architecture, and innovation—but I didn’t know Kotlin or anything about building an Android app.

At 84, I wanted to solve a modern problem: mainstream family‑safety apps have become surveillance tools that drain battery and track 24/7 history. I set out to build a privacy‑first utility that checks location on‑demand via SMS and email, without requiring the receiver to install an app.

I hired an AI assistant—Google Gemini—not to “do it for me,” but to act as my hands while I provided the brain.

Architecture

The solution required four distinct technologies to communicate securely:

• Android App (Kotlin) – runs on the phone and manages GPS.
  I acted as the Technical Director, describing logic flow, error handling, and privacy constraints. Gemini acted as the Junior Developer, writing syntax and refactoring based on my testing.

Below is a look under the hood.

Challenges

Challenge 1: The “Sleeping” Phone (Kotlin & Firebase)

Android’s Doze Mode kills background network access when a phone is idle, making remote wake‑up difficult. I needed a reliable way to trigger a location check even when the device is in deep sleep.

// Generated by Gemini, Architected by Terry Mechan
if (action == "buddy_location_request") {
    // Critical: Use WorkManager to guarantee execution even if app is killed
    // My contribution: switched from IntentService to WorkManager with setExpedited
}

Challenge 2: The “No‑App” Interface (PHP)

The receiver (the Buddy) should not need to install the app; they simply click a link. I required a secure, expiring‑link system that validates a token against a MySQL database before allowing a location request.

Challenge 3: The Data Structure (MySQL)

We needed to link “Buddies” (requesters) to “Users” (phone owners) without storing unnecessary personal data. I sketched the schema; Gemini wrote the SQL.

CREATE TABLE sms_authorized_requesters (
    -- columns definition here
);

Result

After 12 months of iteration, testing, and “arguing” with the AI (yes, you have to correct it!), the result is a robust, published application. The code is efficient thanks to Kotlin Coroutines. This project proved that AI does not replace human experience—it amplifies it, enabling an 84‑year‑old to build a product that typically requires a team of five.

Where to See It

• Philosophy: Read more about my concept of “Sharing without the stalking” on the main website: [PlaceMe Guardian Homepage]
• Tech Demo: Try the technology right now without installing the app (Web Simulation): [Try the Web Demo]
• App: View the live release on the Play Store: [MyBuddy on Google Play]