Mobile has several factors which make it ideal for communicating with your customers at their moment of need, provided you respect the need for privacy and permission. It also allows for hyper-local and interactive marketing, which can greatly increase engagement.
People spend more time online than with any other media. Much of that time on mobile, and most time on mobile is spent in apps, which makes apps a dominant form of digital interaction (Convince & Convert n.d.). Consider carefully whether your business really needs an app.
If you do decide to run a mobile-focused campaign or create an app, you need to make sure that you implement it carefully and, as always, measure and optimise as you go along.