Yes, you can use BookBook on your white iPhone 5. Unlike the polycarbonate exterior of the white MacBook, the iPhone 5 has glass a glass and aluminum exterior, so there are no materials that are susceptible to discoloration.
COVID-19 Virus Update: Twelve South remains open and appreciates your continued support and business immensely. However, due to our team working remotely, the only way to reach us is via email. We monitor email closely and will typically reply the same day during normal business hours (see below). Please reach out with your order number, concern or question at firstname.lastname@example.org.