[pentae]

In a perfect world all app devs would have 10 iPhones To be able to test across all different hardware. Of course, that would be ridiculous.

[tspike]

It's even worse: one of each device for every OS version supported, which Apple themselves make exceptionally difficult as it's nearly impossible to downgrade to older OS versions.

[village-idiot]

That’s actually pretty common. The cost of testing hardware is much much lower than the cost of the developer making the app.