Last month, Twitter announced the launch of a new “playbook” for app developers. It includes what Twitter describes as a series of how-to guides that walk developers through the process of building an app.

A spokesperson for the company tells WebProNews, “We know firsthand that it’s hard to build successful iOS and Android apps. We’ve built quite a few and we’ve learned a lot about how our partners build apps and tackle problems. At this year’s Flight conference, we showed off the power of some of the new features from Fabric with two apps that we created and open-sourced on GitHub: Cannonball, a magnetic poetry game, and Furni, a mobile-first furniture store. “Based on our experience building Cannonball and Furni, we’ve organized what we’ve learned into a playbook.”

The first part, published last month, covered prototyping, design and stability. Other parts talked about account systems and social login, creating a backend to manage services, data, and identities, and adding data from third-party APIs.

There’s a new part available now and it’s about making money from your mobile app.

Learn how to make money from your mobile app in our latest #MobileAppPlaybook post. https://t.co/4cBorX9MMHhttps://t.co/3dV3pgDcMo

— TwitterDev (@TwitterDev) February 5, 2016

“You can begin planning how you’ll earn money from your app even if you’re not ready to implement anything yet,” writes Twitter developer advocate Bear Douglas . “Lots of successful apps have wildly different strategies — from freemium models to ad support, to direct sales of goods and services. To decide on the right strategy, you need to answer a few questions about your app.”

Such questions include:

“Can you just charge people for it outright?”

“Are you selling anything, be it physical goods, in-app purchases, or subscriptions?”

“Do you have a good place to put ads in your app?”

As Douglas points out, you’ll also want to make sure you’re in the clear to monetize. In other words, you’re not prohibited fromusing certain APIs in paid apps or in conjunction with ads.

See what Twitter has to say about each of these scenarios in the new piece.