Floating Islands Mod 1.7.10 simply makes islands generate in the air. It will actually pull the land up, leaving a crater below. Now a more configurable floating islands experience in the config. Also, they no longer generate on superflat worlds (maybe).
Screenshots:
Mod Showcases:
How to install Floating Islands Mod 1.7.10
Download Links for Floating Islands Mod 1.7.10
For Minecraft 1.7.2
For Minecraft 1.7.10
For Minecraft 1.8