# LLM Builder Kit - Hands-On LLM — Build & Train Your Own AI LLM

> Build & Train Your Own AI LLM (iPhone/iPad app by Yuhsiu Lai.)

- Source: https://appshunter.io/ios/app/llm-builder-kit-hands-on-llm/id6762579598 (this page in markdown: same URL + `.md`)
- Developer: [Yuhsiu Lai](https://appshunter.io/developer/433114647)
- Category: Education, Developer Tools
- Price: $2.99 (on sale, was $4.99)
- Age rating: 4+
- Requires: iOS 17.0 · 5 MB
- Languages: American English
- Released: 2026-04-21
- Data updated: 2026-08-30
- User reviews in markdown: https://appshunter.io/ios/app/llm-builder-kit-hands-on-llm/id6762579598/reviews.md

## What is LLM Builder Kit?

Ever wondered how AI chatbots like ChatGPT, Gemini, Claud actually work under the hood? LLM Wizard lets you build a real language model from scratch — on your phone.
Whether you're a curious beginner or a seasoned developer, this app walks you through every fundamental concept powering modern AI: tokenization, n-gram probabilities, training epochs, loss curves, temperature sampling, fine-tuning, and prompt engineering.
Learn Mode — 10 interactive chapters:

Understand how raw text becomes a trained model, step by step. Visualize attention weights, explore embeddings, and interact with a live language model as you learn. New in v2.0: chapters on Fine-Tuning & RLHF and Prompt Engineering take you all the way to how today's AI assistants are built.
Build Mode — 6-step wizard:

Choose your own domain (fairy tales, movie reviews, cooking, sports, poetry, and more — or paste your own text), configure your tokenizer and hyperparameters, watch your model train in real time, then generate text with your finished model. Save snapshots and compare two models side by side.
Test yourself:

Take a quiz after every chapter, unlock 12 achievements, and track your progress through the full curriculum.
Glossary:

50+ searchable definitions covering every LLM concept in the app — always one tap away.
No cloud. No API keys. Everything runs on-device.
Perfect for students, developers, educators, and anyone curious about how AI really works.


## Version history (last 2 releases)

### 2.0 — 2026-06-29

Version 2.0 — the biggest update yet!
• 2 new chapters: Fine-Tuning & RLHF and Prompt Engineering

• Chapter quizzes — test your knowledge after every chapter

• 12 Achievements to unlock as you learn

• Glossary — searchable definitions for 50+ LLM terms

• Save & compare trained models side by side

• Use your own custom text to train the model

• Share generated text directly from the app

• First-launch onboarding tour

### 1.0 — 2026-04-21

No release notes.

## More apps by Yuhsiu Lai

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- [Engineer's Toolset](https://appshunter.io/ios/app/engineers-toolset/id478486737)
- [Battery Current Simulator](https://appshunter.io/ios/app/battery-current-simulator/id488430945)

All apps by Yuhsiu Lai: https://appshunter.io/developer/433114647

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-30.*