Just got my first iPhone, how do I close apps to save battery?

I have always had android phones and last had the htc evo. I always had an app/widget called task killer that I would tap and it would close all my running apps. Today I got my first iPhone 4 and see there are no such apps however I know I have a ton of things running, how can I close them out/save battery?

Double click the home button and press down on the apps for 2 seconds and then exit it out

Double tap the home button; hold your finger on one of the apps, then click the red "-" for every app.

Double click the home screen. Apps that are open should appear. Press long the app you want to close.

Turn off the notification on general

Double click the front button then hold the app and move it a little. Then click on the red circle! Hope that works for you, it's harder to explain on here then real life, haha!

  • My iphone screen is very dark, but if I look very close, I see the apps slightly? My iphone screen is very dark but I still see the buttons slightly, but I have to look very closely in order to. It is definitely not the brightness, because the brightness is set to 100% and its way too dark anyway. I tried restoring my phone and turning it on and off, but nothing is working. Please help. What do I do? I literally threw it out of anger and its fixed.
  • Just got my first smartphone (iPhone 3GS), what apps should I get? I got the 3GS as it's a cheap first smartphone but I don't know all the common uses smartphones are put to. What uses/apps do you recommend? Can you recommend a good racing game that will run on the 3GS?
  • Just got my first iPhone. Apps? I've never had an iPhone before, and I don't know much about apps. I'd like some recommendations for apps that will make my life easier, and also some that are just fun. What do you have on your iPhone? Thanks a bunch! I got the iPhone 5c.
  • Just got an iPhone 5 should i let the battery drain? Got an iphone 5 couple of hours ago and when i turned it on it was abouit 50%. Its 5% now should i let it drain then charge to 100% apparently i heard thats good to do, not sure?