Installing Wx Form Builder On Mac OSX
Installing a wxFormBuilder binary for mac is very easy and can be done as with any mac OS application.
Download the archive containing the binary and expand it. (If the archive is of .dmg type, you additionnaly need to copy wxFB to your Applications folder and eject the disk image. For .zip archives, only double-clicking them is needed.) Then you can simply open the app by double-clicking, and either keep or throw away the archive file, as you wish.
If no binary is offered for a specific wxFormBuilder version and/or for your processor architecture, you can build from source by following the instructions there : Building from source on Mac OS X. You don't need to follow the instructions in the packaging subsection if all you want is to run it on your computer, however of course it would be nice to contribute a binary for that release/architecture if none exists currently.