How can I find the version number of an iPhone app from the IPA?

There's a better way than PlistBuddy and grep:

unzip -d unzipped-ipa MyApp.ipa
defaults read "$(pwd)/MyApp.app/Contents/Info.plist" CFBundleVersion
rm -rf unzipped-ipa

It's worth noting that using defaults read requires an absolute path to your app.

Do the below from your terminal

    //Unzip the file 
    unzip YourIPAFile.ipa

    //Open payload folder
    cd Payload

    //Open your .app file
    cd yourApp.app

    //Open the plist file
    open Info.plist

You can find the version under Bundle version key