Increasingly, students' personal digital devices -- most notably, their smartphones -- are far newer and more powerful than anything a school can supply. Therefore many schools are letting students and teachers bring and use in the classroom the devices with which they are the most comfortable, an educational version of the work world's bring-your-own-device model. Of course, this brings with it a couple of concerns: security and equity. Many schools do not feel capable of ensuring students' safe use of so many disparate devices. Also, not all students can bring a mobile device to school.