Google Slides are a great way to collaborate on presentations with others. Right now, it doesn't have all of the bells and whistles that PowerPoint has, but the collaborative piece of this is invaluable for students to be able to work together on the same presentation at once. There is also an app for the iPad now called Google Slides that is free to use. Another nice feature of Slides is that you no longer have to worry about forgetting your USB drive or your version of powerpoint being different than the computers...it's all through Google! Which means, as long as you have access to internet, you have access to your Slides presentations.