You don't need a SIM card and cellular service to use most features of today's iPhones and Android phones. Most apps and services run just fine as long as you have access to WiFi, and you can even set ...
Due to in-family upgrades I have an iPhone 5S that no one needs. I'd like to keep it for development purposes, but I don't want to keep track of yet another Apple ID and I don't want to put a sim card ...