AeroDiver is a simple dive planning reference tool for Pebble.
Based on PADI Recreational Dive Planner tables.
With AeroDiver you can set your depth and see your maximum no decompression dive time.
Set the planned dive time, and you'll find the pressure group you'll be in after you surface.
Next step is to add a surface interval, and see how long you must stay above water to reach your desired pressure group.
When you begin your next dive, the max NDT and dive times are based on the pressure group from your previous dive.