I think phones shouldn't be allowed in schools, unless they're used for educational purposes.
Why? Well, I think phones are somewhat distracting and they can make pupils pay less attention in class, which is not a good thing. Also, they have a negative effect on our vision and can damage our eyes in the long run, so I encourage using the phone as little as possible. Of course using our phones is a lot of fun, but we should use them when other sources of information aren't available or when we want to be entertained.
In conclusion, I think phones should be used in our free time.