Download of AppResigner 1.0 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. AppResigner for Mac is included in Developer Tools. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This free software for Mac OS X was originally designed by Brian Gorby.
From the developer:
AppResigner allows you to re-sign an app with a different signing identity or certificate. All you need to do is drag your built app onto the AppResigner icon, enter the destination signing-identity you want the app to be resigned with, and you’re done. You can also launch the app manually and select the app from there.
You may want to check out more software for Mac, such as Witango 6, WitangoStudio or DB Solo 3, which might be similar to AppResigner.