Yes, there is a simple way. Firstly, you have to obtain the Lazarus 1.6.4 for the Mac OSX. Download and install it.
Once it's installed, navigate to the HydroBuddy's main website and download the source file which is hosted on the GitHUB. Open Lazarus, load the main project file from the Source and compile it.
Remember, that it needs to be done solely on the Mac OSX to be able to use it on that operating system.