Q:

How to compile an .app bundle for OSX

I need to create a .app file in order to use my javafx application on osx. 
I already read this, but it doesn't help much...
The tutorial above has a topic "DMG Package" but when I compile my app with the fxbuild there is no .app folder/conainer anywhere(also no dmg).  What am I doing wrong? 

A:

Sample Build Script
Here is a script which creates and installs a .app bundle on OS X.
#!  /bin/bash

################
# package.sh
#
# Packages java code as a native OS X application
#
# - Fetches source for a Java Swing HelloWorld application from the web
# - Compiles the source
# - Packages the source into a native Mac application
# - Installs the native Mac application
# - Runs the native Mac Application
#
# Requires:
#   OS X 10.8+
#   Java 8b77+ (http://jdk8.java.net/download.html) 
#   super user rights on the execution account
#
# To Use:
#   chmod +x package.sh
#   ./package.sh
# As the script executes sudo commands, enter your 
# superuser password as needed. 
################

# select java version
set JAVA_HOME=`/usr/libexec/java_home -v 1.8`
$JAVA_HOME/bin/java -version

# cleanup work directory and any existing application install
if [ -d work ]; then
  rm -rf work
fi

if [ -d /Applications/HelloWorld.app ]; then
  sudo rm -rf /Applications/HelloWorld.app
fi

# create work directory and use it
mkdir work
cd work

# fetch a simple HelloWorldSwing sample java source from the web
mkdir start
cd start
curl -O http://docs.oracle.com/javase/tutorial/uiswing/examples/start/HelloWorldSwingProject/src/start/HelloWorldSwing.java
cd ..

# compile the HelloWorldSwing java source
$JAVA_HOME/bin/javac start/HelloWorldSwing.java

# create a jar file 
$JAVA_HOME/bin/jar cvf HelloWorldSwing.jar start/*.class

# make an executable jar file
$JAVA_HOME/bin/javafxpackager -createjar -srcdir .  -appclass start. HelloWorldSwing -srcfiles HelloWorldSwing.jar -noembedlauncher -outdir .  -outfile HelloWorld.jar

# package the jar and java runtime as a native application with installer
$JAVA_HOME/bin/javafxpackager -deploy -srcdir .  -srcfiles HelloWorld.jar -outdir .  -outfile HelloWorld -appclass start. HelloWorldSwing -native -name HelloWorld

# codesign the application using your apple developer ID (if you have one)
# allows the app to be accepted by the Apple GateKeeper - https://developer.apple.com/resources/developer-id/
# codesign -s "Developer ID Application" bundles/HelloWorld.app

# mount the installer disk image
hdiutil attach bundles/HelloWorld.dmg

# install the HelloWorld application from the disk image
sudo cp -R /Volumes/HelloWorld/HelloWorld.app /Applications

# unmount the installer disk image
umount `mount | grep HelloWorld | cut -d " " -f1`

# leave the work directory
cd ..

# run our newly installed application
open -a HelloWorld

Answers to additional questions

is there no way to create one on windows?  

If you want to create a Mac App, you need a Mac (at least for JavaFX 2.2 or 8 apps). 

WAIT- is this only Java 8?? " Requires: Java 8b77+" 

The script might also work with later versions of Java 7 (e.g. after build 6), but I have never tried it with those versions. 
It definitely won't work with early versions of Java 7 (e.g. before build 6) nor any version of Java previous to that. 

"Requires: OS X 10.8+"

The script might also work on OS X 10.7, but I haven't tested with that version.  
It definitely won't work on 10.6 or earlier (and neither would the app produced). 

tried a java class called app-bundler.jar but that didnt work 

I've never tried app-bundler.jar and cannot comment on what it may or may not do.   This solution does not relate to app-bundler.jar.