I have run across this before but keep forgetting about it. There is a great website called Real Math whose author created over 30 real world math activities based on google earth. I know there is a google earth app for the iPad because I put it on my own. So now I can add it to my classroom set. The author has divided the lessons into 5 groups, concepts, project based, measurement, exploratory and space. Under exploratory, I found one titled whale watch that sounds quite interesting. In addition, he has tutorials and teacher materials in addition to the student materials.
I look forward to trying some of these activities in my classroom so it gives students some experience with seeing the connection between math and real world.
I also got a note about illuminations from NCTM reminding me about this. Unfortunately, many of the lessons require flash and cannot be used on the iPad. Illuminations has 108 online activities and 607 lesson plans. It just means you try some of the activities on your iPad to see if it works. Many of the lessons do work. So give it a look.