With a free account, you can sync your device with the web site every ten days.
If you have two devices, you can sync each of them with the website every ten days. Changes are not automatically pushed out to all of your devices — that’s a Pro feature.
However, if you sync your devices with the web site, your recipes will eventually make it out to all of your devices. For example, if you sync your phone with the website, your phone recipes will be on the website. Then, when you sync your tablet with the website, the recipes from your phone will make their way to your tablet.
If you have a Pro account, you can sync your devices with the website as often as you like. Changes are then pushed out to all of your devices.