From this comment from NLog developer:
It is not about in-app-purchases, but the lack of paid upgrades. It is simply not working to deliver lifetime free upgrades for a few bucks app. The result is that 95% of all apps I bought (and I bought many many) never saw a serious upgrade. The bizz model of the App Store is only supporting one-hit-wonders. Fire and forget. I would have given all NLog classic users a crossgrade option to NLog MIDI, but Apple does not allow this. At the end indie developers will only be able to continue their work, if people are willing to pay from time to time some money which is in most places less than a drink. Paid upgrades would be best, but who is able to direct Apple?
GB – although a quite disappointing app compared to the abilities Apple has – will put even more pressure on indie app developers. And they copied a lot of features from indie dev apps. Further Apple does not care about providing a plug-in model. Although: They have all technology in place. The full Audio Unit stuff is already in iOS and we are using it daily.
Fortunately Google is not doing music apps – yet. But Android still has too much fragmentation.
I have no bet where the community will be in 6 or 12 months. But the Audanika story is not very encouraging.
At the end it all depends if we are finding enough creativity and energy to develop music apps which user are willing to pay for. It is in our hands, but Apple is not always helpful.
If it isn’t already, then pricing is going to become a big issue for developers and not just music devs, but lots of others too. Personally I’d be more than happy to pay for upgrades so long as you can opt to skip them if you wish, and I accept that not all updates work as in-app purchases.