From Grosh 4.X list syncing works differently. In previous versions of Grosh, it did it all the time, for even the smallest change on a list. From Grosh version 4, if modifications exist, they are batched together and synced as a whole. This can be manually done using pull-to-refresh (place finger on the list and move it downwards a bit, then release finger) or press the refresh icon shown top right. If you don’t do so, the app will sync by itself within 10 seconds (only as of Grosh 4.1.1) or by itself the next time it is launched. The same applies if you’re out shopping and marking stuff as purchased – again you should use the pull-to-refresh or tap the refresh icon to sync. This will let you know if your spouse added something to the list while you’re in the store.
The change significantly reduces network traffic and makes it possible to use the app when you are completely without network coverage, e.g. in an underground grocery store.
Note: If you pull-to-refresh while the Grosh servers are unavailable, you will see a message about being offline, and that you can continue to use the app.