Automation is a very powerful feature where you can let the program automatically change mixer controls like volume, panning and mute at any point in time. You can use it to create fades, boost your solo's, etc.
You will see that the samples will get a faded colour, the Edit button changes in an 'Automation Add' button and the Split button will change in a 'Move Automation' button.
It's best to zoom in vertically as far as possible on the track you wish to enter automation for. The vertical space on each track represents the parameter range for the parameter you select in the Automation Panel. For example, volume goes from -infinity to +6dB: the top of each track will then represent +6dB and the bottom will represent -infinity. Inserting automation points anywhere between top and bottom will set the selected parameter to a certain value in between. You can see this value in the Automation Panel on the left when adding or moving automation points. Lines will be drawn between successive automation points: the mixer will follow these lines on playback and adjust the parameter (like volume) in real-time according the position on the line.
Scroll button: behaves the same as in normal mode: move your sample display around freely without affecting any automation.
Add button: tapping on the screen will add an automation point. To help you position the point more accurately, you can move around the point after adding it if you don't release your finger from the screen. The parameter value will be displayed at the left pane.
Move button: tap near an existing automation point to move it around. Note that you cannot move beyond the next and previous automation points.
Range button: unused at the moment
Remove button: slide your finger across the screen to remove automation points.
At the left of your screen, you will see that the mixer channel has traded places for the automation panel. Here you can select the parameter you wish to edit (volume, mute or panning), The Clear button will allow you to create all automation events of the selected parameter type for the selected track.
Underneath these buttons, you will see a parameter value display, This display gets updated when you are inserting or updating an automation point.
When no automation for the selected parameter is available, you will not see any automation lines drawn. When you enter your first automation point however, two points will be added! One at time 0:00, and the other where you enter your automation point. The reason is that, when playing back, the program must know at which parameter value to start. So, before entering your first point, it's best to think about where you want that parameter to be at the start of the project. For instance, if you want to create a fade-in, first set the channel's volume all the way down (-infinity) before entering automation mode. Then enter automation mode and add the automation point where you like your fade-in to end. Now you'll see a line drawn between 0:00 at -infinity and where you clicked (for instance, 0:10 at 0dB).
Similarly, when you want to create a fade-out, first make sure your volume fader is set to 0dB (or wherever you want it to start), then scroll over to your fade-out point, enter automation mode, add your fade starting point at 0dB. You'll see a straight horizontal line from 0dB at 0:00 to 0dB at your start of fade. Now enter your fade end point at -infinity to the bottom right of your fade starting point. You may enter additional points in between to shape your own curve.
Although the lines are straight, for volume parameters the changes are logarithmic: the upper third part is for 0dB to +6dB, the next third part occupies 0dB to -6dB and the lower part is from -6dB to -infinity.
Note that because the buffer sizes on Android are usually higher than on PC's, fades can sound less smooth than expected. During mix-down however, a smaller buffer size will be used to more smoothly render your parameter changes.