"I purchased WW for my daughter's mobile phone. She was spending too much time in Facebook, and WW app was advertised as a good solution for it. Unfortunately it didn't work as supposed - phone user (I tried it by myself first) can disable or even delete the application using default app manager. Because of this the whole purpose of parental control feature is usless.
At the same time I must say that if you don't delete the app it works normally, so it's 3/5 from me."