A familiar billing screen
Work with products already available in the local catalogue, instead of learning a second billing tool. Saved prices and settings help build the bill, but changes made elsewhere will not appear until the device receives fresh information.
Sales with a visible status
A pending record tells you that the sale is saved locally, not yet confirmed in your online accounts. After successful sync, it can be matched to its final invoice. This makes it easier to explain an offline receipt and check that nothing was missed.
One device, one saved queue
Each counter keeps its own unsynced sales. Another phone or computer does not automatically hold a copy of that queue. Keep the original device available and allow its sales to finish syncing before changing browsers or clearing stored data.