Limiting smartphone use for children
The advent of the smartphone is so recent that parents and educators are still trying to understand the implications for children. On the positive side, smartphones offer instant communication with family and friends and have become a key part of a child's social interactions.

The advent of the smartphone is so recent that parents and educators are still trying to understand the implications for children. On the positive side, smartphones offer instant communication with family and friends and have become a key part of a child's social interactions. However, there is increasing concern about children developing dependencies on their electronic devices. Smartphones are designed to be irresistible; combining dynamic social networking with messaging and games is guaranteed to be attractive to most students.
The key is balance. The temptation is to wade in and remove the phone, but that only provides a temporary fix. Rather than removing temptation, you want your son to be able to use his phone responsibly and you can create some areas of control in his life that will allow him to do so.
A study by the Helsinki Institute for Information Technology identified three main rewards users receive when they check their phones: information, such as checking the time or a news update; interactivity such as Facebook updates, which might trigger a discussion; and awareness such as checking for new e-mails, which give the user the impression that their universe is changing. It is the desire for these three rewards that explains why people check or touch their phones on a regular basis.
Perhaps removing his phone permanently isn't a good idea, but there may be times when it is less distracting for it to be out of sight. These could include when he is studying, or needs to complete another task that requires focus. This may cause unhappiness, but your concerns indicate that this strategy will be worth pursuing.