Link: https://frida.re/

Install

Install Frida Client (on the OS): pip install frida-tools

Install Frida Server (on the iOS/Android):

• Android - Download from Frida Github (https://github.com/frida/frida/releases) the version you need for Frida Server (For Genymotion it will be frida-server-14.2.18-android-x86.xz ). Extract and push to the android devices using adb push frida-server /data/local/tmp and install by going to android shell and chmod +x frida-server and execute the file.
• iOS - Download Frida from Cydia by adding the Frida source 'https://build.frida.re' and then searching 'Frida' and install.

Check it works by running frida-ls-devices

Frida Tools

• frida - The main tool, spawn a new process and execute command in there
• frida-ls-devices - show devices that frida can access
• frida-ps - show a list of processes on the device that Frida can attached to
• frida-kill - terminate a process
• frida-trace - Allows us to trace specific functions
• frida-discover - discover internal functions in the program
• frida-compile and frida-create - compile c modules and execute

Frida Modes:

• Injected - Used on Jailbroken devices, frida sever needs to be installed on the phone. Spawn a new process of the application with the Frida hooks.
• Embedded - Used on non-jailbroken devices, no need for frida server on the devices. You need to repackage the app with the frida gadget already embedded.

Repackage a app:

If you want to use Frida on a non jailbroken (/rooted) devices, you will need to repackage the app.