This is an area that iOS severely needs to work on. Android actually handles this much better and definitely kills apps in the background. They also need to make a less awkward way of closing apps than the double click and then hit the tiny x's. A swipe gesture would help a ton, but another thing that android, windows phone, and bb10 have going for them is the dedicated back button can be used to back out of an app which closes it vs the home button which will leave it in the background. Closing an app in iOS is very annoying and cumbersome in comparison. Android's swipe to close in the multitasking window is nice as well. Apple also should have discontinued the ipod touch 4th generation a long time ago. 256mb and the a4 chip is just not enough today. Even the 5th gen and the ipad mini should have 1gb of ram.
The 5th gen iPod and ipad mini only have 512mb but yes I do agree 256mb ram isn't enough. I use a jailbreak tweak on my iPod "killbackground" to easily kill all apps in one button press.