Introduction to Cydia Substrate
Cydia Substrate is a tool for runtime hooking and modification of Android apps by injecting into the app process on rooted devices. This was formerly known as Mobile Substrate, which was originally released for iOS devices. Cydia Substrate is the base for most of the runtime manipulation tools that are available. We can develop third party add-ons that work using Cydia Substrate. These are known as extensions. The next section shows a tool called Introspy, which is a popular Cydia Substrate extension for runtime monitoring and analysis of Android apps. Cydia Substrate is available on the Google Play Store and you can install it from the following link:
https://play.google.com/store/apps/details?id=com.saurik.substrate
Once you install it, Cydia Substrate's home screen will come up as in the following figure if you launch the application.
Tap on the Link Substrate Files button and you should see the following activity:
Upon the first installation of Cydia Substrate...