Tap the Download button to claim a free prize
You will notice early on in the game, in the upper right side of the screen, a Download button. Tap on that and it's going to start downloading some game resources immediately. You can do this after you've started playing, or later - it doesn't matter. Just make sure that you do it, because once you've finished the download you will be able to claim the reward for free, which will give you the following items.
Big Grow Pack (contains various stones and other upgrade items)
100 Sapphires.
500k Gold.
2x 150% EXP Potions.
Make sure that you claim this because you will have plenty of Gold then and the extra 100 Sapphires will help you later on in the game, so it's definitely something worth getting for free!