At least in the case of mobile ordering at Starbucks, that app sounds like it's adding real, additional value: It allows you to do something you otherwise can't

At least in the case of mobile ordering at Starbucks, that app sounds like it's adding real, additional value: It allows you to do something you otherwise can't do without the app. Aside from the digital receipt thing (which, in my opinion, is really only useful if you are planning on returning an item or collecting receipts for tax deduction) where is the additional value with the mobile Walmart app?