The three principles they listed for their model have served me well in apps I've written, especially the first (immutability). Most of the Apps I write rely on

The three principles they listed for their model have served me well in apps I've written, especially the first (immutability). Most of the Apps I write rely on some kind of server data so it works really well. I'm writing a recipe book app as a learning project and I'm experimenting with just saving JSON to the App's document folder as a persistence layer.