If one app (or website) has really improved and increased creativity in my workflow, it's Canva. I was swooning after the first 10 minutes of finding their website and haven't stopped since. I'm no graphic designer and this platform makes me look like one! Even though I almost always create in Canva on my laptop, it's free app is easily accessible to students with Google accounts. Its cloud-based library is only one feature I love. There's the "get design inspiration" (formerly known as Stream) that's chocked full of ideas to get me pointed in a new direction. The "design essentials" (formerly known as Design School) gives users interactive tutorials and also features a blog and teaching materials.
Create graphics for web or for print with templates for social media (Facebook, Twitter, Instagram), posters, presentations, flyers, cards, brochures, menus, infographics, blogs, invitations, and more. I use Canva constantly with iMovie and with web design. When you need a great graphic, need to add text to a picture, or make a collage, Canva's a platform worth exploring. Free and inspirational, it's a great place to start with student app smashing (Canva + ThingLink, Canva + Animoto, Canva + Puppet Pals, Canva + THE LIST COULD GO ON AND ON...) Check out this Pinterest board for inspiration!