If you want more Diamond or anything such like that follow these steps.

Find 9 pieces of diamond, or special item.
Next craft the diamond block or desired item, from the crafting table.
then place the block down somewhere.
After you have placed the desired block down press the home button of your iPhone, iPad , etc.
Then finally double click the home button of your device.
Keep double clicking it until you see the app slot where it has your previous played apps.
Then holed the " MineCraft " app until it has a red negative sign on it. Press the Negative sign. The app will still be there but not where your previous ones where right then.
Now turn your phone off, wait about 3-5 seconds then turn it back on.
Once you have done that step go back too the app and the world you were in.
Now go too the place which you have placed your desired block down. Once you are there you should see the block where you have placed it and the same exact block in your inventory.
If you keep repeating this step over and over again you will have lots and lots of diamond , iron , gold , etc. * This Should work if you are doing it right. I have over 2,000 diamonds !!!! Because of this trick. It's easy , it's fun , and it should work.