You can earn either on iPhone/iPad or Android phone/tablet with Quick Thoughts. Quick Thoughts will give you iTunes credits if you cash in from your iPhone or iPad, or, if you redeem from Android tablet or phone you get the Amazon credits (doesn't matter which platform you performed the tasks on). Recently, they updated their IOS app to IOS10 and if your device is not capable of that you're out of luck for either doing or redeeming on Apple devices.
User Testing has iPhone tests too. The site says you have to have at least IOS 10 though I know for the iPad testing they sometimes say it has to be IOS 11 or 12.