http://iscoresports.com/

Will the iPad app work on the iPhone too or do I need a separate app for that?

Thanks!

The iPad app will not work on the iPhone. You have to get the specific iPhone app.

Is the data interchangeable? In other words, can I use my iPad to look at data gathered on my iPhone (and visa versa)?

Yes, you can use Data Sharing to transfer data between the devices. Here is a link that describes data sharing:

http://iscoresports.com/baseball/kb/faq ... _share.php

many of us transfer data from device to device iPhone, iPad, android regularly without any issue once you learn the method of data sharing mode...