mulle-agvtool updates your CocoaPods podspec version in synchronicity with your Xcode project.
It also allows to have a CURRENT_PROJECT_VERSION setting like this
CURRENT_PROJECT_VERSION="$(MULLE_APP_VERSION).1848"
This is an extended version of the Apple Xcode agvtool script. Technically it's just creating a patched copy of the original script.
just clone the repository and then say make to create your mulle-agvtool. You need to have Xcode installed.
There is a demo Xcode project that documents how to use mulle-agvtool.
See the source...