How to design online class activities and how to make the best use of
the available internet technologies, especially
of mobile devices to activate students learning.
I often start a class with a Mentimeter survey. It helps get students' attention as they use their mobile phones to answer the survey. In addition, the interactive survey promotes active engagement of students and prepares the basis for discussion of difficult topics. The free Mentimeter version is enough for me for now.
I often use triventy for online quizes at the beginning of the class. Students answer the questions about previous lecture. The fist 3 students get a little bonus at the exam. As it is like a competition it motivates them to at least open my presentation and refresh some knowledge.
Also sometimes I use online boards (even simple and not so suitable for this as diagrams.net connected with google drive). It helps me to show the audience some features online and get some feedback from them. Also I do it if I need too show something and don't have a possibiliti to use a flipchart.