Android is a Unix-like operating system. It interprets Linux commands using its own Toolbox and/or BusyBox. And leveraging this power, there are certain situations when you need to run shell commands at boot. If you don’t want to mess with init.d or other system folders, you can find applications that run commands at boot for you—applications like Boot Shell.
Boot Shell was created by XDA Senior Member gh0stslayer. With this application, users can easily define shell commands that are executed at boot. The application can execute simple commands like copying a file or making a list of installed apps in /data/app/, and it can also be used to activate kernel-related functions like overclocking, undervolting, governors, and loading custom modules. It’s pretty easy to use, as all you need to do is to enter the command that you wish to execute, and add it to boot or as a favorite command.
If you are on a rooted stock ROM without init.d functionality, or simply want to add some shell commands at boot, make your way to the application thread and give it a try._________