Keith - I assume the the ipad app is similar to the android app - which doesn't copy data from your computer - it downloads it from the Ancestry tree. The app only downloads the main structure, names etc. Images are only downloaded if you try to view them. Most of your 7Gb will be census images etc. - it certainly doesn't take 7Gb to hold 1500 names and dates. Also the PC program has much greater functionality than the app, and includes data such as historical timelines which won't appear on your app.