Getting iHeart Radio for iOS 7.1.2

Have had for a long time iHeart Radio app (v.5.8.0, Build 2) on my iPhone 4 (iOS 7.1.2) & love it. Tried to put same app today on Hubby's iPh (same exact phone & iOS) & it keeps saying "this app is only for iOS 8.0 & higher" but I guess since it's a 4, we can't get a higher iOS than 7.1.2? Tried a radio app that would go on his ph & it *** compared to iHeart; any way we can get iHeart onto his ph? (And am I gonna eventually lose iHeart on my ph since it looks like only iOS 8 & higher is supporting them?) Thanx for any help.