Here's one that came from the post-CELTA support group which I run at IH Barcelona, where there's recently been some discussion of Edmodo and where someone asked if ClassDojo wasn't the same sort of thing.
Not really, I don't think: they're in fact designed for two completely different purposes.
Edmodo [ tour ] is Facebook, basically. If you sit a teen down in front of Facebook and come back many hours later and s/he will be happy and not want you to bother her/him, and will have communicated with 100-200 people in some way, plus done a ton of other things. Could you harness some of that for English language learning?
Personally, because of privacy issues, I wouldn't want to use Facebook with learners; Edmodo I definitely would use with teens, first of all because it would be primarily the learners using the technology and provide total privacy.
Classdojo [ tour ] on the other hand, is essentially the teacher grading learner behaviour and not the learners using the technology at all. If you had 15 (or 25!) kids in each class, and "graded" each learner 5 times in every hour, how many clicks would you have to make over the course of a week? Wouldn't you be better spending your time actually attempting to modify (not merely grade!) their behaviour?
Classdojo would be a fascinating tool for a behavioural psychologist or other researcher, but I can't see its practicality for the classroom teacher.
Or have I missed something…?
Footnote | Our (totally private!) support group has been running since 2004 and in fact still uses a Yahoo Group (not Edmodo!). For adults, who (unlike teens!) still use e-mail, I can highly recommend it.