A couple of APT users with Macs running OS X 10.8.3 (the latest Mountain Lion and Java 1.7) have reported that they are getting a message that the APT dmg file is damaged, and that their Macs recommend putting it in the trash and are not letting the application run.
We have verified that the dmg file is not damaged. Since we have verified the APT tar.gz installs and runs normally, it is not a Java 1.7 issue.
The simple solution is to allow apps to run from anywhere. This can be changed via
System Preferences > Security & Privacy > General Click on the lock icon at the bottom of the panel to unlock and make changes. Under "Allow applications downloaded from", select the "Anywhere" radio button.
Mac users may wish to re-enable security after successfully installing APT.
A more detailed write-up of the procedure is shown at
A helpful overview is post #6 on this page:
Another APT user got the dmg file to open by doing this:
1) Run the Ruby script at http://snipt.org/kto/ on the executable to remove signatures. Then the message changes from “damaged” to “from unidentified developer”.
2) Control-click “Open” on the APT dmg file, and select select Open.
3) From then on, double-clicking on the app in Finder works.