To move around the world, you can pinch in and out, swipe with your finger, tilt the device to rotate the scene, and use the scale bar to the left.
The point of the game is to explore what exists inside human hands! You can zoom into different types of cells, different parts of the cell, and molecules. You can get points by touching elements on the screen.
You can get to the lab by pressing the icon (up there to the right). In the lab, you can see more about elements you've collected. When you've collected enough, challenges are unlocked, which get you mega-points.
The bar on the bottom of the screen is a ruler that tells you how big things are. It's in regular units, as well as scientific notation. If you press it, the decimal places are drawn out for you.