If the specs or host OS change along the way, it's a new contract and the old is toast.
You can ask for a no charge fix but sorry I have to side with the developer as they didn't change, Apple and you did.
Back in March, I hired a contractor to develop iOS and Android apps for an agreed upon price. The project has run longer than expected, which I anticipated and am fine with.
I've been testing the apps and providing feedback about issues; but both apps have been working. iOS 10 was recently released and whenever my testers, who've updated to iOS 10 try the app, it completely crashes; however, I have NOT updated to iOS 10 and the app seems to work fine.
My developer wants to charge me more to update the iOS app to make it compatible with iOS 10. I'm opposed to paying more because the app completely crashes and in my opinion, the app isn't incomplete if it doesn't work at all on the newest OS (iOS 10). I want to be fair to the developer; but, I also don't want to pay for something I've already paid for. The developer's argument is that the app is ready and works on the previous OS (iOS 9) and that his development obligation is complete.
My question is, am I being unreasonable by expecting the developer to make the OS updates to get the app working on the current OS at no additional cost?
A quick note, the Android version of the app seems to be working well on the new OS (Nougat). Thanks in advance for your perspective.