I Built an AI Spam Blocker App as an Indie Developer (NoSpamPro)

Why I Built NoSpamPro

Like everyone else, I was tired of scam calls, betting SMS, and fake promotions. Important messages were getting buried under spam, and unknown callers were constantly interrupting my day.

Instead of just complaining, I decided to build a solution.

What is NoSpamPro?

NoSpamPro is an AI-powered spam SMS and call blocking app designed to be:

• Fast


• Offline-first


• Privacy-friendly

The main goal is simple: stop spam without collecting user data.

Privacy-First by Design

Most spam blocker apps rely on cloud servers to analyze messages and calls. That means your personal data may leave your device.

I didn’t like that idea.

NoSpamPro follows a privacy-first approach:

• Core detection works offline


• No personal data is uploaded


• No account or subscription required

Security should not be sold.

How It Works (Simplified)

NoSpamPro uses a hybrid detection system:

• Lightweight on-device AI models


• Rule-based spam filtering


• Keyword and pattern detection

This allows the app to detect spam without heavy cloud processing.

Current Features

• AI-powered spam SMS detection


• Automatic call blocking for suspicious numbers


• Offline detection engine


• Multi-language support (EN, TR, ES, PT, HI, RU, DE, ZH, FR, ID, TH, KO, AR)


• Completely free to use

Challenges I Faced

Building an AI-powered mobile app as an indie developer is not easy:

• Performance vs accuracy trade-offs


• Battery and CPU optimization


• Platform limitations (especially iOS)


• Fighting false positives

But shipping a real product taught me more than any tutorial.

What’s Next

I’m working on:

• Better on-device AI models


• Community-driven spam pattern sharing (privacy-safe)


• Performance optimizations


• Researching iOS limitations and possible solutions

Lessons Learned as an Indie Developer

• Ship fast, then iterate.


• Privacy is a strong product differentiator.


• Users love simple and free security tools.


• Distribution (ASO, SEO, communities) matters as much as coding.

Final Thoughts

NoSpamPro is my attempt to fight spam and digital harassment with AI.

If you’re interested in mobile AI, privacy, or indie development, I’ll share technical deep dives, growth experiments, and mistakes here.

Thanks for reading!

— Hüseyin Sarı