I don't know how many people know of this, but I though I'd explain how to duplicate items in survival. This allows you to turn one item into two, two into four, four into eight, and so on. It works with any item but only one type of item at a time. 1: toss the item(s) out in front of you. 2: pause and quit to title. 3: enter back into your world. 4: pick up the item(s) and walk forward. Keep walking away for at least 30 seconds. 5: when you are far away from where you started, exit and force quit minecraft. 6: enter minecraft again and enter your world. 7: walk back to where you started. The items that you tossed out should still be there, in addition to in your inventory. Pick them up and you have twice as much as you started with. 8: repeat as many times as needed. You can start with just a few items, and build up a full stack in no time. You can even duplicate multiple stacks of the same item, for example turn four stacks of diamonds into eight. This method is very handy for getting large amounts of materials such as quartz and glowstone that are only created in a nether reactor. It can also help you get enough gold to build a nether reactor. As far as I know it works in 0.7.1 and 0.7.2 on iOS.