My Take
Overall, if your school/district has purchased this program, I would recommend using it with your students. I would use it a few times in class to make sure that all of the students know how to log on and then let students use it at their leisure. Many of my students said that they read more because it was a lot easier to read on their phone than carrying around a heavy novel.
How I Use It
I assigned MYON assignments primarily as homework assignments. I also used the app for our "Drop Everything and Read" series.
Pros
Assesses students' reading levels
Recommends texts to read based on student interest survey and reading levels
You can assign texts to students (good for enrichment, or a thematic unit)
Provided benchmark assessments
Has texts in Spanish (good for new arrival ENL students)
Logs students time spent reading (great for competitive students)
Provides various prizes to top students in their program
Cons
Student interaction to the teacher through the app is limited
limited range of (engaging) higher level texts
limited range of classic novels
requires a paid subscription through your school/district
need to remember a username/password (no log in with Google option yet)
cannot share data for one class across multiple teachers (a coteachers nightmare)