Best answer by Ken_Griffiths
Sonos System Requirements
The software is free to all, but you need a device that is capable of running it. I would personally hold Apple to account, as they were the ones who were quite insistent that App developers switchover to 64 bit versions of their Apps. Apple have stopped supporting 32 bit... and your device!! See link below.
It’s not Sonos' fault. The cheapest way to deal with this is to perhaps get an Amazon Fire 7 Tablet, or similar device. Often these can be obtained for around £/$30-£50 or thereabouts, depending on the various deals available.