I wanted to get down some thoughts on apps. In essence :- it's not really about the app... let me explain.
All "apps" cater to some basic (and usually pretty old) need/desire - let's take "listening to music"; I (like many people) now use music streaming services like Spotify, Google Play Music and Apple iTunes and many more.
Why do I pick one "app" vs. another?
1. Content firstI like classic rock, when Spotify did not have Pink FLoyd or Led Zep - I looked around for an alternative. Now they have those artists, I use their service. The right content is the "mandatory" part of the app. So what makes me "loyal" to one app/service.
2. Ease of Access
The next thing that differentiates one "app" from another is how easy is it to use. Sure App UX is important. But again, I see this as a mandatory/basic thing... what really matters is that I can get access to the content wherever I happen to be. In the living room, in the kitchen, in a car, on a train in a plane or a hotel room. That means the "app" (really "the service") is largely platform agnostic.
This is where Spotify comes up trumps again: it works on my Android phone, my PC, my iPad, Sonos, the family MacBook our TV etc. And better yet all those devices "know about each other" so I can control the TV from the iPad etc.
It also lets me listen to music offline (e.g. when travelling). Again, it's the content where I want it, when I want it.
The last and most crucial aspect of differentiation is the degree to which the app/service recognises me and adapts itself to me. Let's stick with music streaming: over time I have built up a library of playlists and "saved" a bunch of albums I like. This represents some personal equity in the service - I created these, it would take time and effort to create them somewhere else.
That's where music streaming stop short of how far they could go. They have my listening history. With that they could offer (maybe they already do) big data powered personalised recommendations. You seem to like The Stone Roses and Led Zep in the morning; maybe you would like this... that listening history is much more difficult (impossible?) to move from service to service.
In essence personalisation offers me (the user) value/features - but in turn raises the switching costs associated with an app/service.
If you get all three of these right - then you have a good "app"; loyal customers and a potentially lucrative business. But did you notice how little of it is really about "the app"...