Yes, perhaps an indie dev looking for an app design. On Upwork I've had people ask me for dev agencies once the design is complete, so many people view it as a separate process. Though I need to think about my ideal customer some more.That's interesting. It's true that there aren't many pure mobile apps design agencies. Most agencies have in-house design, but there might be a niche there for you. What would be your ideal customer? I can think of small teams of developers trying to build an app with 0 design skills, but maybe there are other types of customer?
The thing is, with mobile apps there's a formula that all the big apps have discovered. You ask for a trial signup immediately on first app open, and get them to subscribe yearly. There's $30-$80 outright (after the trial). Many forget to cancel (it's something no one wants to talk about, but is a huge bulk of app earnings). If you have a steady stream of users, a certain % will start the trial, and % of those will not cancel. It's why you'll see mobile apps have mostly yearly subscriptions. You don't have to worry about monthly subscription retention, or any complicated calculations.That's very interesting indeed. One thing that puts me off of mobile apps is that their perceived value seems to be much lower compared to SaaS apps, and there is also the problem with user retention. I read that here Mobile App Pricing: What App Pricing Strategy Works Best? [+tips]
But you've probed that it's perfectly posible, and providing a subscription model helps mitigating these problems.
Mobile apps are also much easier to get users for, because they're on the App Store -- a trusted platform. Paying is as quick as a fingerprint or face scan, and everyone trusts Apple. Facebook and other platforms directly link up to the App Store. Who trusts a new SaaS app, where payment involves entering credit card info or opening a new PayPal window? It's much harder.
Though a downside is you rely on the App Store.