Ya know, for the amount of time of how much people look at their devices, or even the amount of time people spend moralizing about others looking at devices - there is a dearth of sober reflection on the strengths and weaknesses of the technology.
I'm no philosopher, so am not going to be able to offer a deep probing discourse, but over the last few years in pondering the role of apps in architecture/real estate some aspects have come into sharp relief.
The most obvious is that apps are a pretty poor investment as standalone sales tools for real estate. You might consider one to extend your property's branding but I think if you look at the analytics - the number of downloads that lead to good buyer leads is appallingly low.
The relationship between buyer and a potential property is necessarily casual from a negotiating standpoint at the buying phase - and that casual relationship is much more easily modeled as a website or realtor's page with dozens of possible properties that the buyer can peruse - than an app which requires commitment.
Apps require a commitment.