How to move your character
When the bottom three petals are pressed, the flower will produce downward momentum. So if the flower is in the air, his motion will be downward in the direction chosen. When the left or right direction petals are selected, the flower will turn in the direction indicated and move horizontally in that direction (if it is not blocked). Note that all three left petals cause the flower to turn left, and all three right petals cause the flower to turn right.
For a quick jump a short amount to the right, try tapping the petal shown above a couple of short taps. Watch what the flower does. Repeat with the upper left petal to see the flower jump backward a short amount. For a longer jump press and hold the upper right petal and watch as your flower jumps farther than with a quick tap. Same for the other directions. For a more rapid jump to the right, try moving first in the horizontal right direction and then sliding your finger to the upper right direction. Your flower will jump farther if you get a running start this way.
Here are the in-game tutorial images for controlling your character.