I've been using ClassDojo for at least five years. Its core features are behavior tracking and parent communication. They've adding a new feature: Portfolios. In the past, I used Seesaw for student portfolios. It's a pretty good setup and the students were good with adding to their portfolios, and parents liked it. But it was just one more piece of technology I had to manage, so I dropped it.
Back in the beginning, I had the typical behavior pocket chart with green/yellow/orange/red tags. I used to manage the tags myself, then handed off responsibility to the students. It's not a very positive approach, so I dropped it as soon as I heard about ClassDojo.
ClassDojo is also great for data analysis, as you can watch for trends and check aggregate data on students and behaviors, then download a datafile. Dojo provides instant feedback to parents who want to know how their kids are doing. It's also discreet as long as you don't display your screen for all to see. Nobody else needs to know how well that child is behaving. You can also tie a reward system to their points if you so desire.
I have a Google Voice phone number I use for voicemail and text messages. I've had that number back when it was GrandCentral. It's free and nobody needs to know your personal cellphone number.
I can count on one hand how many text messages I get during the school year. Involved parents have the ClassDojo app on their phone and text me that way. They also use email for longer messages. I get a lot of traffic in my Dojo messages section. It also helps that I'm looking at my ClassDojo app throughout the day as I monitor behavior, so I see parent messages pretty quickly.
The messaging feature also lets me send a message to all parents at once. I always start with "To all:" so they know it's a broadcast. Dojo doesn't distinguish between the two types of messages at the parents' end.
I already mentioned SeeSaw. It does a great job of supporting multiple formats such as audio, video, and still pictures. But now Class Dojo has similar features. The teacher can pictures or files to a student's portfolio, or the student can add their own media that needs to be approved by the teacher before it shows up in their portfolio. Portfolios are private and can only be viewed by that student, their parent(s), and the teacher. This requires significant management time, so I just use the Stories feature for general sharing, and Messaging to send a parent a snapshot of their child's work.
ClassDojo has good documentation for setting up an account. You might have to remind parents to use your provided link to connect to their kid's account. Some parents accidentally sign up for a teacher account.
Since I team teach, I create a class for each Math/Science group I have. ClassDojo wants first and last names for students. I only use a last initial to add some privacy for my students.
A class starts with a default set of positive and negative behaviors to track. I just import the settings from my previous year's classes, which I've archived. As a sidenote: when the year ends, don't just delete the kids from your class so you can recycle it for next year.
Give it a try! It's free and I've always received positive feedback from parents. The only concerns I hear from parents relate to keeping a child's behavior status private, but that's my general mode of operation. Students don't get to look at my screen, and I don't announce point totals or negative points.