Numbers is the native iOS spreadsheet program. It does not come free with your iPhone or iPad, you will have to purchase it from the iTunes App Store. It is designed to be a very simple and easy to use spreadsheet program.
This movie is designed to be an introduction to numbers. It is not designed to tell you everything you need to know, is designed to get you started.
The movie starts with introducing you to the settings in Numbers, on an iPhone. It goes on to create a simple spreadsheet to keep track of your expenses. The movie then goes on to open this spreadsheet on iPad. iCloud allows you to store your spreadsheets online and access them from either your iPhone or your iPad.