Facebook SDKs enable you to pass app event data from your app to Facebook. With app event data, you can accurately track and measure the actions people take in your app.
If you have not already done so, specify your app's platform in the app settings. Open the App Dashboard for your app, choose Settings > Basic, and go to the Platform section.
If you provide your app on multiple platforms, repeat this setup for each platform where your app is available. For example, if your app is available on both Android and iOS, you should set up platforms twice in your app settings - once for the Android SDK and a second time for the iOS SDK.
At this point, the SDK is set up, and your application can pass app install events to Facebook for measurement and tracking purposes. With this data, you can track and measure app installs and also optimize your ads delivery for mobile app installs. Now that you've implemented the SDK for your platform, you should also add code for additional app events you want to track and measure, such as purchases.
For full instructions and documentation on Facebook SDKs, see these guides: