I would recommend taking a look at this blog review of Ask 3. We have several teachers in East Noble School Corporation that are already implementing it.
How one teacher is using it is to record a lesson on the Every Day Math math boxes. There are usually one or two questions on the math boxes that cause the students quite a bit of frustration and require extra attention. By recording them before the math lesson, the teacher is able to field a lot of questions. The students can also replay the video if there is a misunderstanding. She feels it makes her more efficient as a teacher.
As far as the students actually responding to each other’s questions, that has not happened yet. I will keep you posted as I meet with teachers using the application.