To fix android monitor app in OSX try this:
0) Install java jdk 8 version under or equal 8-151
1) Go to monitor-x86_64 folder in mandoid-sdk
2) Right clico on monitor.app and chose "Show Package Content"
3) Go to Contents folder and open Info.plist in any text editor
4) Find section "<key>Eclipse</key>" and uncomment line "<string>-vm</string><string>/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin/java</string>"
5) Correct this line with valid path to your eatly installed jdk. Save It.
6) Run monitor.app. Enjoy.