AI App Builders: $0 vs $25/mo — 5 Tools, 5 Free Courses

Someone on X posted their Lovable bill last week. $1,125. For one month. On an app that wasn’t even finished.

This isn’t unusual. Across every AI app builder — Lovable, Bolt.new, v0, Replit Agent — people are burning through credits, tokens, and dollars because they picked the wrong tool, used the wrong workflow, or just never learned how the pricing actually works.

And then there’s Google AI Studio, which quietly launched full-stack app building for $0. Zero. No credits, no tokens, no monthly fee. Most people still don’t know about it.

We built a free course for each of these five tools. Not surface-level overviews — full 8-lesson courses with quizzes and certificates, focused on what matters most: building real apps without wasting money.

Here’s how to pick the right one.

The Five Tools at a Glance

They look similar on the surface. They’re not. Each one solves a different problem, charges differently, and has a specific workflow that — if you don’t learn it — will eat your budget alive.

Lovable: The Full-Stack MVP Machine

Who it’s for: Non-technical founders who want a working product, not a demo.

Lovable is the fastest path from “I have an idea” to “here’s a working app with a database, user accounts, and payments.” It generates clean React code with built-in Supabase integration, meaning your data actually persists. No extra setup.

The catch? Credits. Lovable charges per message, and costs vary by complexity — a simple color change costs about 0.5 credits, but adding authentication costs 1.2+. Beginners who send changes one at a time instead of batching them end up spending 3x more than they need to.

What our course teaches: The PRD-first workflow (plan in ChatGPT, paste into Lovable), batching strategy that cuts credit usage by 60%, design systems in one prompt, and the full integration stack — Supabase, Stripe, Telegram, Vercel deployment. Total cost for a complete MVP: under 100 credits.

Take the Lovable course (free, 8 lessons)

Bolt.new: The Code-Aware Builder

Who it’s for: People who want to stay close to the code while AI does the heavy lifting.

Bolt.new runs entirely in your browser through WebContainers — no local setup, no installations. It hit $40M ARR in five months, which tells you something about demand. But the token system trips people up. Unlike Lovable’s per-message credits, Bolt charges based on tokens processed. And here’s the thing most people miss: the biggest token cost isn’t your prompts. It’s Bolt reading your entire codebase every time you send a message. Small project? 50K tokens per prompt. Large project? Over a million.

The saving grace is Bolt’s three modes. Build Mode updates code (expensive). Plan Mode discusses your approach without touching code (cheaper). Discussion Mode is pure conversation — 90% fewer tokens. Most beginners never leave Build Mode. That’s expensive.

What our course teaches: How the three modes work and when to switch between them, the .bolt/ignore file for controlling what AI reads, file locking, MCP Connectors (Notion, GitHub, Jira), and Bolt Cloud’s built-in database with security scanning.

Take the Bolt.new course (free, 8 lessons)

v0 by Vercel: The UI Perfectionist

Who it’s for: Anyone who cares about how their app looks — or works within React/Next.js.

Here’s something the comparison articles don’t emphasize enough: v0 generates the best-looking code of any AI builder. Not just visually — the actual code quality. Components are modular, properly typed in TypeScript, and follow patterns a senior React developer would approve in a code review. Lovable and Bolt produce code that works. v0 produces code that’s clean.

The trade-off? v0 is frontend-first. It’s not trying to be a full-stack platform like the others. Database, auth, backend logic — you’ll need Supabase or another service for those. And the pricing uses three AI model tiers (Mini, Pro, Max) with different costs per token, which makes your monthly bill unpredictable if you’re not careful.

What our course teaches: When to use Mini vs Pro vs Max models, the Figma-to-code workflow, technical steering with Tailwind CSS classes, Supabase integration for backend, and one-click Vercel deployment. Plus honest guidance on when v0 is enough and when you need to bring in a more full-stack tool.

Take the v0 by Vercel course (free, 8 lessons)

Replit Agent: The Everything Platform

Who it’s for: Anyone who wants mobile apps — or needs more than just a web app.

Replit Agent is the only tool on this list that builds iOS and Android apps. Not web apps pretending to be mobile — actual React Native + Expo apps you can publish to the App Store. A doctor used Agent 4 to build his entire clinic stack in two hours: a landing page, a booking platform, a full iOS app, a promo video, and a client presentation deck. All from one platform.

Agent 4 (launched March 11, 2026) introduced parallel agents — multiple AI agents working on different parts of your project simultaneously. One handles the backend while another designs the frontend while a third sets up the database. And the Infinite Canvas lets you generate design variants, compare them side-by-side, and apply the winner directly to your app.

The pricing uses effort-based credits that scale with complexity. Economy Mode is cheap. Power Mode costs more but handles harder tasks. Turbo Mode (Pro only, $100/month) uses the most capable models. Core plan credits don’t roll over — use them or lose them.

What our course teaches: The parallel agent workflow, building and publishing a mobile app (the full Expo pipeline), using the Infinite Canvas for design, creating slides and videos (not just apps), and budget management across Economy/Power/Turbo modes.

Take the Replit Agent course (free, 8 lessons)

Google AI Studio: The Free Disruptor

Who it’s for: Anyone who wants to build full-stack apps and pay exactly nothing.

When Google launched full-stack vibe coding in AI Studio on March 18, the reaction on X was immediate: “Every vibe coding startup just had a very bad week.” And that tracks. Lovable charges $25/month. Bolt charges $25/month. Google AI Studio charges $0. No credits. No tokens. No monthly fee. Just a Google account.

The Antigravity agent is surprisingly capable. It auto-provisions Cloud Firestore when your app needs a database. It sets up Firebase Authentication when you need login. It handles multiplayer state for real-time collaborative apps. It supports React, Angular, and Next.js with modern tools like shadcn, Framer Motion, and Three.js. And Annotation Mode lets you draw directly on your app’s UI to describe changes — no typing required.

The downsides are real, though. It’s new. It’s tied to Google’s ecosystem (Firebase, Cloud Run). Deployment to Cloud Run is free for small projects but may cost money at scale. And there’s a persistent worry in the community: “feels like it’ll start charging soon.”

What our course teaches: How the Antigravity agent works, Firebase database and auth setup, building multiplayer features, connecting external APIs with Secrets Manager, Annotation Mode workflow, and deploying to Cloud Run (including what the free tier actually covers).

Take the Google AI Studio course (free, 8 lessons)

Which Tool Should You Start With?

Still not sure? Here’s the decision tree:

“I just want to build something fast and I don’t want to spend money.” Start with Google AI Studio. It’s free and surprisingly powerful.

“I have a business idea and I need a working product with a database and payments.” Start with Lovable. It’s the fastest path to a real MVP with Supabase and Stripe built in.

“I want to build a mobile app.” Replit Agent. It’s the only platform that builds native iOS/Android apps.

“I’m building within the React/Next.js ecosystem and I care about code quality.” v0 by Vercel. Best UI code, one-click Vercel deployment.

“I want to understand every line of code and I want control over the stack.” Bolt.new. The three modes give you the most flexible AI-assisted development experience.

The Credit-Saving Cheat Sheet

Every tool has a version of the same problem: beginners waste money because they don’t know the optimal workflow. Here are the highest-impact tips across all five:

What Each Course Covers

All five courses follow the same structure: 8 lessons, 2.5 hours total, beginner-friendly, with quizzes and a certificate. Each one is tailored to its specific tool:

The Real Question

A year ago, building an app meant hiring a developer or learning to code. Six months ago, you needed one tool and a lot of patience. Now you have five platforms that can turn a text description into a working application — and the main skill isn’t coding. It’s knowing which tool to pick and how to use it without burning through your budget.

That’s what these courses teach. Pick one. Start building.

Sources:

• Lovable Plans and Credits — Lovable Documentation
• Bolt.new Pricing — Official
• v0 by Vercel Pricing — Official
• Replit Pricing — Official
• Google AI Studio Build Mode — Google AI for Developers
• Introducing the New Full-Stack Vibe Coding Experience in Google AI Studio — Google Blog
• Replit Agent 4: Built for Creativity — Replit Blog
• Maximizing Token Efficiency — Bolt Support
• Best AI App Builders in 2026 — NxCode
• V0 by Vercel Complete Guide — NxCode