114 Pages · 12 Chapters

The SecureFlutter Handbook

Secure your app without needing a security team.

Follow Jeffrey, a developer shipping a real app, as he makes, and fixes the same mobile security mistakes most Flutter apps ship with. Twelve chapters with a checklist you can run against your own app when you're done.

Get the Handbook

The Secure Flutter Handbook · Mobterest Studio

AUTH SECURITY

SECURE STORAGE

PKG VETTING

ZERO TRUST

CERTIFICATE PINNING

JAILBREAK DETECTION

OAUTH 2.0

FLUTTER SECURE STORAGE

MAN-IN-THE-MIDDLE

CODE OBFUSCATION

BIOMETRIC AUTH

SQL INJECTION

Inside the Handbook

CH.01

Improper Credential Handling

CH.02

Insecure Data Storage

CH.03

Insecure Communication

CH.04

Insecure Authentication

CH.05

Insufficient Cryptography

CH.06

Insecure Authorization

Plus five more chapters on client code quality, code tampering, reverse engineering, extraneous functionality, and jailbreaking detection, and a bonus chapter on AI and mobile security.

What's In The Book

Everything you need to understand, implement, and audit mobile security in Flutter.

11 Practical Chapters

Each one follows a real app fixing one real mistake.

The Toolbox

A full audit checklist at the end; intelligence gathering, mapping the app, running the tests, and reporting what you find.

Bonus Chapter on AI

How AI is already changing mobile security for attackers and defenders.

Who This Book Is For

A Flutter developer building mobile apps who wants to secure them from day one.

A beginner mobile developer who has heard of "OWASP" but found it overwhelming.

A solo developer or freelancer responsible for both building and maintaining your app.

Someone who prefers step-by-step guidance, practical examples, and gentle structure over dense textbooks.

This book is intentionally written to feel like a supportive checklist, a friendly companion, and a practical reference all in one.

What's Included

Your purchase gets you more than just a PDF.

The eBook (PDF)

114 pages of beginner-friendly, field-tested guidance.

Private GitHub Repo

Code snippets, secure patterns, and ongoing updates.

Discord Community

A community of fellow devs (optional), no noise.

Free Updates

Not a static book. You'll always get the latest version.

Lifetime Access

Yours to reference, reuse, and revisit forever.

Doodle-Friendly

Make notes, highlight sections, treat it like a companion.

Why I Made This

Security always mattered to me but I never found a resource that taught it in a way that felt approachable. I wanted more than a list of terms to Google later. I needed a step-by-step reference, clear "what and how", and a format that felt light and practical and not like another college textbook.

This is that guide. And now it's yours, too.

One Developer. One App. Twelve Mistakes.

Every chapter follows Jeffrey, a developer on the verge of launching ParkEasy, as he ships a mistake — and an attacker finds it before he does.

Chapter 1

Jeffrey ships ParkEasy with credentials sitting in plain sight, and learns exactly how an attacker finds them.

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

const mistake = {

what: "hardcoded credentials",

found: "in 4 minutes",

};

Chapters 2–6

He thinks each fix closes the case. It doesn't. Storage, communication, authentication, cryptography, and authorization each open a new door.

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

const stillBroken = {

storage: true,

auth: true,

crypto: true,

};

Chapters 7–11

The mistakes get subtler (code quality, tampering, reverse engineering, jailbroken devices), the ones most tutorials skip entirely.

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

const skipped = {

byMostTutorials: true,

byThisBook: false,

};

By the end

You're not just reading about Jeffrey's mistakes. You have a checklist to make sure they're not yours.

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

import 'package:flutter/material.dart';

class MobileArchitecture extends StatelessWidget {
  const MobileArchitecture({super.key});

  final String pattern = 'clean_architecture';

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Mobterest')),
      body: SafeArea(
        child: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            final product = products[index];
            return ProductCard(
              title: product.title,
              onTap: () => context.push('/products/${product.id}'),
            );
          },
        ),
      ),
    );
  }
}

class ProductCard extends StatelessWidget {
  const ProductCard({
    super.key,
    required this.title,
    required this.onTap,
  });

  final String title;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Text(
            title,
            style: Theme.of(context).textTheme.titleMedium,
          ),
        ),
      ),
    );
  }
}

const you = {

readTheStory: true,

ranTheChecklist: true,

};

Get the Handbook