http://cambridgeenglishonline.com/Cartoon_Maker/ and http://www.wittycomics.com/ .
So, the reason I am talking about two comic creators in one post is because they are both very simple to use and because of their simplicity they can be used with students in any grade. These comic creators can be particularly useful for students in grades K-2. (You would be surprised what Kindergarteners can do with just a little guidance!)
So how do they work?
Both of these comic creators have interfaces that allow you to simply click with the mouse to add backgrounds, change characters, and add text bubbles. With the Cambridge cartoon maker you can make comics with one, two or four panels. With the witty comics creator, you only have the choice of creating a three panels for the comics. While both comic creators are simple to use, the two main down falls of the creators are: one requires an e-mail address to save comics, while the other creator does have an option to save but you can't reopen the comic to work on it later and that the characters/props are limiting. Having said that, however, they are still useful tools to help students with simple story telling, re-telling or sequencing. In terms of students saving their work, my suggestion to you would be have the students write out their drafts before they create them online, or simply have them print out what they have created when the class period is over.(Especially since Kindergartners most likely don't have e-mails) Then during their next class period they can work on the next panels for their comics, print them out and use scissors and glue to put their printed comics together as a story. See below for a quick comparison between both creators:
Witty Comics:
First, students must pick which comic creator they want. They can choose regular comics or superheroes. Then they will be asked if they want a one, two or four frame(panel) page. Then you will get the comic interface which looks like the picture below: