Hello, I have an old iphone 3GS that I only use for working out and logging my workouts with ifitness and occasionally browsing the internet. I have a Galaxy S3 which I use for my cellular needs. For some reason the multitasking doesn't work between ifitness and the music app, when ever I am in the ifitness app and go to the home screen and use another app, the ifitness app has to start up again if I tap on it. It might be the app itself I suppose. As the title suggests, which version do you guys think would run the fastest and most efficient on the 3GS? Currently I have IOS5.1.1 I tried updating to IOS 6.1.3 through the settings->software update section but it failed (I forgot exactly what happened) and I had a hell of a time getting it back running with IOS5, maybe it's because I have my phone with a jailbreak. Thanks!