Kroger's service is called ClickList.. Walmart has a grocery pickup service in my area too. You order online, and then go pick up your already shopped for stuff at the store.
Shipt is different. It's affiliated with a variety of stores in my area....Publix, Target, Costco, and Kroger too. You list what you want online from whichever of these stores, and your Shipt shopper pulls the items, in touch with you the whole time to see what substitutes will be acceptable if they're out of the thing you want, asking whatever questions if something's not clear, and then delivers right to your doorstep.
There are similar apps here for food delivery too. Gone are the days when the store itself offered delivery. Now, through UberEats as one example, DoorDash as another, you can order from any restaurant and with those apps you can have it delivered straight to your door.
Do these services cost? Yeah, but considering the cost of gas and wear and tear on vehicles, not to mention the wear and tear on my nerves, sometimes it's just the best option!