If you are developing an iOS app and you want to test it on a real device or if you want to distribute it to the App Store, you have to sign your application. This ensures that the user knows that your app is coming from a known and trusted source that Apple knows.
This guide was created to help iOS developers with code signing and to ease the sometimes painful process.
Here are a couple of links to get you started
This guide is open source, you can find the sources on GitHub, just simply select the GitHub repo from the top right corner or click on the pencil icon on any page to edit it's contents.
If you find a typo, would like to add or modify a content, feel free to update it and to send a PR.