How to write a cydia app

I was wondering about to create a cydia tweak running on iphone startup a开发者_如何转开发nd hooking some iphone feature as sms or call.

So I wanted to know where should I start:

1. How to write a cydia application (xCode? Toolchain? which toolchain? how to install it?)
2. Where can I found documentation about the hooking methods of the mobile substrate?
3. How can I star my application on iPhone startup?

I'd be glad if someone can link me THE VERY NOOB guide on how to start jb developpement (I juste develop "officially")

Thanks everybody

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I know there are other ways of doing this, but if your a licensed iOS Developer you can simply sign the code in your App and put it on to one of your registered testing Devices that's jailbroken and follow the step by step instructions below:

Download iFile from the Cydia Store. I would suggest paying for it, but you can find other sources where you can get a cracked version. Then use iFile on the device and go into the following directory: var/mobile/Applications/YourAppName Select YourAppName.app folder Tap the zip file button, (between + and trash buttons at bottom of display) You will be prompted to name the zip file and hit create. That's the zip file you submit to Cydia, you can email it to yourself from within iFile, or if you want use a program like DiskAid to pull it from your Device. DONE!

TESTING To test you need to copy the .app file into the following directory: var/stash/Applications Exit iFile and Delete your app from the devise. Respring, Reboot, or Restart.
The icon will then be on your desktop.

HOPE THIS HELPS SOMEONE!!!

Note: This is against Apple policy, but if you don't tell I won't ;)