The ability to push notifications of events and promotions to customers is useful in many contexts. For example, a restaurant or local brick and mortar retail store could notify customers of current promotions or remind them about customer loyalty rewards that may be available.
Geotargeting allows app developers to set certain geographic perimeters that trigger alerts and notifications. For example, if a loyal customer walks within 3 blocks of a retail location, they may get a notification telling them about the latest promotion.
Does your business thrive on referrals? You can use an app to track and reward past and current customers who refer their friends to your business.
An app can also make it very easy to share content to social media. Did your customer just find a great blouse on your rack? Did a new customer just realize they've been missing out on the best burger in town? Your app can make it easy for them to share that information with their friends.
Mobile apps don't always have to be business to consumer, though. They can also be used to arm your sales force. Do your salespeople need access to up-to-date inventory and product details away from their desks? Do you have contractors in the field who may need to reference other local projects in an area when speaking with prospective new clients? Mobile apps can provide an access point for those salespeople to get the information they need to close a sale.