WASHINGTON — Buying groceries with your smartphone can help you save money and get home quicker.

For instance, with Safeway’s improved app, you can create a shopping list that will tell you where each item is in the store.

The app’s homepage now gives you a quick look at how many 10-cents-off-per-gallon gas rewards you’ve earned, and when they expire.

Elsewhere, stores like Wegmans and Harris Teeter let shoppers use their apps to refill prescriptions. Some Giant Food stores will let you scan your own groceries with your smartphone and bag them as you go. Find a recipe you like through Whole Foods Market‘s app; with one tap, you can add all the ingredients to a shopping list.