I've tried opening on an alternative OSX 10.11, 10.8 and 10.6 and at least one of those does not have apple's java. All fail to open. The highest java version I have is 8.

It's an instant startup fail which leads me to think you might have forgotten to change something.

I suspect you might have forgotten to change a reference. Perhaps renaming the name (or version) of the launching app. Although the plist file looks ok. CFBundleShortVersionString 0.01 I don't know if that's correct? Or perhaps forgotten to change the internal java version reference (though I see there's a reference to 13 in the jre folder)?

Generally most of what you have allocated into the MacOS starter folder usually goes into the Resources folder of the package so it's a new approach to me. Might help explain why the plist file is relatively small.

But a PkgInfo file appears to be missing that would normally be alongside the plist file for most apps. First time I've looked at the contents so I cannot compare with a previous version. However I think I saw a reference in the plist file that would normally be in the pkginfo file.

There appears to be a lot of references to mail within the app. Does that mean the dev(s) are monitoring everyone's MW (and system)?