Standard presentation software on Apple computers. App available for purchase to run full presentation software on iPad also doubles as a presentation remote ($9.99)
Google Slides (Google)
This is a solid, functional presentation package. It is not as user-friendly as Keynote or PowerPoint but is does get the job done for free and the finished package is easy to share. Use presentation software such as Doceri ($30.00) to control and annotate your presentation from an iPad, or simply project from a pad through Apple TV.
Free education account for teachers. Very similar to Keynote, but a bit more limited. Presentations are stored in the cloud so you can access them anywhere. Subscriptions are available for accounts with more features. Like Google Slides, can be operated from an iPad through Doceri or other computer remote software.
Presentation software in Office Suite. Standard for most teacher computers, it is probably what you have on your teacher computer already. Again, you can use Doceri or other remote apps to run your presentation from an iPad.
Inspire (Promethean Planet)
Software used to create interactive whiteboard slides (“flipboards”) for projection on a Promethean board. Similar to SMART Notebook, but a bit more versatile. Inspire is free IF your school system owns any Promethean products (interactive board, Actiote or ActivInspire clickers, etc) and, unlike older versions of Notebook, does NOT require a Promethean device to be detected on your computer to fully run the file. Inspire files can be used interactively with any short throw projector, It could be worth your time to check with the IT people in your district, or take a look around your building for Promethean hardware.
Software/app combo that allows you to control your computer through your iPad without having both devices on the same wireless band. You can open or close any file including iTunes, annotate on projected images, run and record presentations (with audio!), project a digital whiteboard, and much more. Requires a software download for your computer ($30.00) and app for iPad (free).