Download of RainClassroom 5.2.2 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The software belongs to Education Tools. This free Mac app was originally developed by Tsinghua University & Academy Online.
From the developer:
Rain Classroom lets you make and send teaching materials to students using WeChat. You can encourage students to participate in discussion, and add more fun to your class. Once the questions are sent, the students' answers appear in time. The demands can be be formulated as objective questions or open questions.
You may want to check out more software for Mac, such as ChordPhobia, Learn To Draw or Fast Rabbit Typing, which might be similar to RainClassroom.