---
title: "Guides"
---

*Developer Handbooks*

# Deep-dive guides for mobile subscription developers

Comprehensive, book-length handbooks covering in-app purchases, subscriptions, and the infrastructure behind them. Read online or download as PDF.

[Explore](/guides/revenuecat-android-sdk)

## Android Monetization Starts Here

Two expert hubs. Two implementation paths.

## The RevenueCat Android SDK Handbook

In-app subscriptions without the boilerplate. Covers the same 18 topics as the Google Play handbook, solved with RevenueCat SDK — less code, managed backend, and one boolean for entitlement checks.

[Start reading](/guides/revenuecat-android-sdk)

## The Google Play Billing Handbook

The complete manual for building in-app purchases from scratch — BillingClient, Developer API, RTDNs, subscription state machine, and every edge case in between.

[Start reading](/guides/google-play-billing)