You can follow the Objective-C packages you are using in your projects for your iPhone dev work and as soon the next version is released you will get notified via email.
If you are using CocoaPods as package manager you can directly upload your Podfile to VersionEye and you will see the out-dated dependencies. This here is a simple Podfile.
platform :ios pod 'SSToolkit' pod 'AFNetworking', '>= 0.5.1' pod 'CocoaLumberjack' pod 'Objection', :head # 'bleeding edge' generate_bridge_support!
It defines 4 packages for the project. If your project is on GitHub, VersionEye can directly monitor your Podfile in your GitHub repository and notify you as soon there are updates available for your project.
The CocoaPods integration is a very new feature. We rely on your feedback. Please let me know if you find something odd or your have further feature requests.