The app has no "user interaction", in other words you cannot move bubbles with your fingers, or do anything other than relax and staring at them. This is also on purpose – on a real lamp you cannot "touch" bubbles, and the app is meant to be a realistic simulation.
Everything is calculated in real time with complex math formulas (the app calculates lava bubbles shape, position, and heating, and also interactions between bubbles, rotation and many more variables).
The app comes in a Light version, and also a Donation-ware Pro version which allows to change the physics, viscosity, bubble radius and cooling time.
The app supports QVGA, WQVGA, VGA and WVGA.
Read more and download the app here.