There you can open it and edit it anywhere with a web browser or a copy of Office 2013. Additionally, there are free PowerPoint apps on Android, Windows Phone, iPad and iPhone.

While it offers you a seamless PowerPoint experience, the Web app does not offer all the features you'd find on the desktop PowerPoint software.

Having two presentations open in separate windows also lets you transfer details – and even entire slides – from one to the other with both open at the same time.

Collaborating on files can be difficult if you use Keynote and someone else uses Microsoft PowerPoint. We show how to fix this by editing .pptx files on your Mac, iPhone or iPad ...

Haiku Deck lets you tell your story in pictures rather than text-laden slides. It's easy to share your iPad presentations and export them to PowerPoint and Keynote.