https://github.com/robhogan/rn-xcode-git-version.git
This simply pacakges the very useful shell script by Gabriel Rinaldi, posted at http://gabrielrinaldi.me/ios-app-versioning-with-git-tag/
To use:
yarn add @rh389/rn-xcode-git-version../node_modules/@rh389/rn-xcode-git-version/version.sh as a build phase to your xcode projectName | Type | Description
-----|------|-------------
-b| number | Optional, default=0. Increase the calculated CFBundleVersion (based on number of commits on this tree) by the given number. Useful when continuing a build sequence from a new repository.