Game is stupid, full of ads and meaningless. You can finish a level without collecting a single gem and upgrading your jewels and shop is totally meaningless since you barely earn anything from it and money are totally useless. They tried to give a feeling of investing to earn more but since it's not even needed to complete a level it's totally pointless. Play in aereoplane mode so you won't get any ads. Game is made by a lazy dev that doesn't even bother in making decent looking levels.