I personally find myself using Google Drawing more often than anything else. I find it much more practical as it is already integrated with Google Drive and so everything I create on it is automatically saved to my Drive account. Google Drawing also has a simple and easy to use set of drawing tools which I am pretty sure your students will enjoy working with. I have already written a detailed visual guide on how to use Google Draw to create classroom posters, I invite you to check it out here.
There are also several good alternatives to Google Draw which you can find below. This edshelf list is curated by Holly Witt and I came across it in teachthought.com.