For distribution of IOS apps created using Xcode, you must build the IPA using the provisioning profile. Following steps will help you to create the provisioning profiles :
1. Go to : http://developer.apple.com
2. Click the “Member Center” Link on the page at the top right. Or you can directly go to the url : http://developer.apple.com/membercenter/
3. Fill out your Apple developer user name and password and click Sign In.
4. Now you have to click the link “Manage your certificates, App IDs, devices, and provisioning profiles.” under “Certificates, Identifiers & Profiles”.
5. In this page, you will see a set of options under “IOS Apps” section. From this choose “Provisioning Profiles”.
6. In the next page, you will see the list of provisioning profiles you already added (if any) or an empty list if you are new to it.
7. You can click the “+(Add)” button on the top of the page to add a profile.
8. Once you click the add button, you will be provided with three options :
a) IOS App Development : This is under the Development section. This provisioning profile will help you to install the development apps on test devices.
b) App Store : This is under the Distribution section. This provisioning profile will help you to submit your app to the App Store.
c) Ad Hoc : This is under the Distribution section. This provisioning profile will help you to install your app on a limited number of registered devices.
9. Once you select an option, click the “Continue” button.
10. In this page, you have to select the app id for which you want to create the provisioning profile for and click the continue button.
11. In the next page, you have to choose the certificate you want to use for the profile and click the continue button.
12. In the next page, you will have to select the set of devices which you want the app signed with this profile to be able to install. And Click the continue button.
13. Now wait for the profile to be generated. Once generated, you can click the Download button to download the profile or you can go to add another one.
This is how to create provisioning profiles for signing your IOS apps.