iSlide is described as 'all-in-one PowerPoint add-in. Handy design tools. 180k+ built-in resources' and is an app in the Office & Productivity category. There are more than 50 alternatives to iSlide for a variety of platforms, including Windows, Online / Web-based, Mac, Linux and iPad. The best alternative is Prezi, which is free. Other great apps like iSlide are Google Slides (Free), Reveal.js (Free, Open Source), Sozi (Free, Open Source) and Keynote (Free).
Visme is the only design tool you’ll ever need to tell and present your stories and translate boring data into stunning visual formats right in your browser. A perfect marriage between PowerPoint and a design tool allows anyone to create visual content with ease.
Takes a few hours to catch on, but makes the most professionally typset documents with a large number of amazingly useful features not available from other types of presentation software. For presentations, consider the Beamer or Prosper document class.
Aspose.Slides for Cloud is a REST based API that allows developers to read, write & modify a PowerPoint presentations in cloud. It is platform independent API & can be used by developers in web, desktop, mobile & cloud applications alike.