Driver

Driver modify value with function, allowing for extra effects to be apllies on top of the normal keyframe interpolation.

Enable curve view so clearly see how the driver will effect the value.

Interface

To add driver, right click on the keyframe in the animation panel. Then select "Driver" to open the driver dialog

First, you need to select type of the driver you want, then you can modify the properties.

Linear

Linear driver will add/subtract the value per frames. This allow for linear increment with only one keyframe.

Wiggle

Wiggles the value randomly. You can set the seed, frequency, amplitude, and octave. The sync axis option will meke the wiggle amount the same for each member in an array.

Sine

Apply sine wave to the value.