I've had a few teachers ask me lately about options for students to interact online. They're usually looking for some sort of discussion forum, where students (and teachers) can post ideas and responses. Here are a few options, with some brief descriptions of each. Ideally these will be tools that you also use for other purposes with your students, but discussion forums might just be one way to start getting students involved in blended learning.
Students use their school Google accounts, teachers (and students) can create groups for specific discussion topics or for general class discussions.
If you are using this already, your class has a default general discussion forum. You can also create additional discussion forums for specific topics or groups of students.
This is designed primarily as a discussion forum, but it also includes some of the features of Moodle such as the ability to upload files and collect assignments. Unlike Google Groups and Moodle we don't create user accounts for students, they need to create their own accounts and then join your class using the appropriate code.
A quick and easy way to set up an online discussion for a day (or longer), it doesn't require student accounts or any other preparation.
There are other options, of course, but these are a few that we use often. Let us know if you'd like help implementing any of these or other tools.