Haiku Deck is a clean and simple to use slideshow tool for the ipad. When you create slides it uses the words you have used and suggests images for you to select from. The clear layout makes for simpler and more effective presentations.
Slideshow+HD is a useful app which allows users to create short slideshows using their photos on their iPad. You can add in effects from a limited range and you can use music from your iTunes account to accompany the slideshow. One word of warning though, if you upload to YouTube you need copyright free music or you cannot share your video. I created this one straight after downloading the app in around five minutes and I am sure that with more practice it could be a reasonable slideshow. Check out my first attempt! I am sure that students could use this in the classroom.
Check out this video on YouTube:
This slide creation site allows you to mash together video, slides and music to create a new presentation. This goes beyond PowerPoint. I recently created one and won Slidebomb of the Day with the web2.0 tools slideshow.
Since I posted this I have won the ‘Slideshow of the Day’ on this site. You can check it out here.