If you can tolerate a 4.5" display, I would recommend LG Realm for Boost Mobile ($40 @Best Buy). I bought two, none of them is activated with the carrier. I just use them as Wifi machines and media players. Realm has a microSD card slot, so I put a 64GB card on each of them, and hook them up to Bluetooth speakers. WOW! That's gotta be the cheapest (and great) mp3 player you can find. Best of all (for me at least), its system language option includes Japanese, so I promptly set one up for learning purposes. Can't say the same thing about my N9, N900x2 or Moto X (my Sony Experia Z Ultra of course has no problem).