Each level has its own income and recipes, and everything saves automatically. Switching levels keeps the others as they are. Bonuses are shared by all levels.
Tap an icon to change its colour. Income per second, as the game shows it. Smelter and crafter recipes take their ingredients from this list, so you only update numbers here.
All levels, recipes, bonuses and settings. Copy it and keep it in Notes or a message to yourself.