GoFormative.com, is a free service for assigning questions to students and having them answer on their laptops or tablets in real-time. One of the best features of Formative is the option to have students draw responses to your questions. A couple of months ago I published a video about that feature.
Another feature of Formative that stands out is the option to give students feedback in real-time. You can give them feedback in a points system or you can give them written feedback in real-time. In some cases, like in the case of a multiple choice question, you can use both feedback mechanisms to help your students understand their mistakes. The video below demonstrates how to use the written feedback function in Formative.
Applications for Education
Letting students see the results of their work in real-time is a nice feature for them and for teachers as it can guide everyone in identifying what they need to spend more time studying. From a practical standpoint it might not always be possible to give every student written feedback immediately. In that case the written feedback mechanism is still helpful as your students can check later to see an explanation from you of why their answers were incorrect.