Currently, when using the array modifier, you can't apply any rotation to the instances. This quickly becomes very limiting because when creating meshes that make use of repeating patterns , the only way to do that is to use an empty object, and that quickly makes the model much more complicated than it needs to be. You always need to keep track of that empty and make sure it moves with the mesh.

This update simply adds a rotation input, which allows you to achieve rotation without using an empty object.

It's not meant to replace the empty object functionality (because it's extremely useful in some cases), but simply add an extra dimension to the default array functionality to allow more complex array modifier uses without having to use empty objects all the time.

Later, more could be added, like adding a way to define the axis of rotation, adding scaling etc.

I've added screenshots to show the usage:

Before:

After:

Example use case:

Edit:
Drastically simplified the code by using the existing functions available in the codebase.