The benefits of your app should justify the cost of setting one up. A profitable app will help your customers engage with your business and make transactions. For example, one problem with e-commerce mobile websites is that it can be tedious for customers to enter shipping and credit card information on a small phone screen. Apps can store customer data, making it more likely that your app users will actually make a purchase.Apps also can allow you to send push notifications to your customers' phones. The Localytics data showed that 46 percent of customers who opt in to push use an app 11 or more times.