I have to start with that I am not a big fan of Twitter . It is not like facebook and it seems to me that it is only for letting people know what you are doing in the last two minutes. Nowadays, it is conquered by a lot of famous people who do not know anyting about the world they live on. They are always fighting with each other and take people's attention to ridiculuos things so in my opinion it is not an area to be used in education, language teaching. Language teaching needs a calm area in which everyone can focus on language only. So far these are my opinions about Twitter. I know I am pessimistic about it but that's what I've observed until now.     

tricider. com

I think tricider is a very useful tool in that it gives each of the students to express their ideas freely ( as now students a re more free with online communication). For the shy students or for students who do not have self-confidence in the class, it is a very good way to make them participate easily in the activities. I would use it when I am teaching something which requires my students' comments and which requires their creativity. It would be nice to prepare them to the subject before the class by proposing an idea and waiting them to comment on this because as they focus on the thing I write, they would not forget what we are working on when they come to the class after a while. 
On the other hand, this tool could turn in an area in which the students write just to compete with each other and this competence could be dangerous because then they would forget the real aim behind it. 
I could add it to my teaching when I run a project with the students. I would want them to share their ideas day by day. They would design the project step by step with the help pf tricider. They could also benefit from other people's ideas. In my opinion, this is a very beneficial tool to share ideas.