iPhone Any apps/tweaks which auto-close background apps after a certain period of time?

[icebergx]

Hi all,
I used to use the tweak BatteryDoctorPro to auto-close open apps that were open longer than 10minutes, to conserve battery life.
BDP doesn't work on iOS7 so are there any apps that do, that replicate this functionality?

Thanks.

 

[icebergx]

Basically, I want something that kills background apps automatically, after they're not used for a certain period of time.