Scrumblr sticky notes are limited to text only. In that regard Scrumblr is basically a no-frills version of services like Wallwisher or Spaaze.
Applications for EducationOnline sticky note services like Scrumblr are useful for brainstorming sessions in which students can quickly share a bunch of ideas with each other. The anonymous online format enables shy students to share their ideas without fear of criticism from other group members.
H/T to Ana Maria Menezes.