Generators are special objects, that are capable of producing items. Similarly to regular items, they can be merged together with identical types - but while regular items will evolve into new objects (e.g. 2 x cherries turn into 1 strawberry), merged generators will turn into enhanced versions of themselves (e.g. 2 x farmers carts turn into 1 big farmers cart).
Generating items requires energy (1 generated item = 1 energy point). Each generator can be double-tapped a specific number of times until they switch to cool down mode (stop generating items). Whether a generator is in cool-down mode or not can be identified by its color - if the background color is yellow, the generator can still produce items. If it turned grey however, the generator is now in cool-down mode and will recharge after a certain amount of time. If the player wishes to skip the cool-down period, they can recharge their generator with gems.