I've had an iFly 700 and 720, but also have used iFly on a Nexus 7 (2013), Samsung Galaxy Tab S2, and an ASUS Zenpad 3S 10. The Tab S2 and Zenpad 3S 10 are both a little long in the tooth now, but iFly still runs perfectly fine on both (the ASUS is my primary iFly device in flight, and the Tab S2 is my main backup, mounted on the copilot yoke within easy reach). Really, unless you pick up a total dog of a device, you'll probably have a good experience running iFly on almost any device. Better devices will have better displays and responsiveness, and those are valuable attributes, but even older devices (like my Tab S2) that have good specs work great.
I also use iFly on a Win10 machine and a Samsung Galaxy S9+ phone, and it runs great on those platforms as well, but those devices are not suited for use in the aircraft while flying, so I only use them on the ground.
One of iFly's substantial benefits is its cross-platform support. Using the app is seamless regardless of what device you use it on, and your settings and stored data (flight plans, sketches, etc.) can be easily moved from device to device.