How to embed your code in android app?

Question

Java

We need to change the application code so that when it starts it displays toast messages (like a watermark). How can this be done?

Answer 1

Good afternoon!
There is such a thing as reverse engineering. Those. you need to download the apk of this application, decompile it, then make your changes, build a new apk and install it on your device.
You can start by exploring these tools:
https://ibotpeaches.github.io/Apktool/
https://java-decompiler.github.io/
https://github.com/pxb1988/dex2jar
Useful information on the topic - https:/ /stackoverflow.com/questions/21010367/how-t...

Answer 2

Get root access, find the file that launches the program, paste the text you need there (there are tutorials in Google), enjoy the program and imagine that you are already a hacker)