I would include Google Drawings in the “swiss army knife of digital resources”. On its own, it is easy enough to create stand alone projects, though it is most powerful when it is incorporated into other aspects of a larger project. Because of its consistencies with other Google publishing platforms, it is extremely easy for students to use independently. It is also beneficial to have students be able to share their work as they would with any other Google doc, make a copy of a template teachers could send out, or whatever else you can think of with using a digital canvas.
Below is one example of how teachers used Google Drawings to create a map that they had student partners duplicate and complete.