Pressing a homerow key moves the tetrad to the indicated column and orients it to its default rotation at the same time. Note the cirle-marked pivot point of the tetrad -- that's the bit which will end up in the column you type.
The row above the homerow moves the tetrad and orients it counterclockwise.
The row below moves and orients clockwise.
Number keys move and orient to 180 degrees.
Space drops the tetrad instantly.
Once you get the hang of positioning tetrads, try auto-drop mode, where every keystroke instantly drops the piece after applying the position and rotation.
As in most versions of Tetris(R)(BS)(WTF) it is possible to scoot a tetrad even after it lands. The trick here is to press the second key before letting up on the first. If you prefer, scoot mode may be disabled. With scoot turned off and auto-drop turned on, every press of every key will instantly play the current tetrad and the next one will become available, enabling the fastest possible play at the cost of scoot moves and any semblance of safety.