The conventional wisdom is that smartphones have become commodities: ubiquitous, interchangeable slabs of metal and glass whose falling prices spell disaster for companies that have come to rely on selling them at high prices.

When most of us first heard of it a few years ago, Snapchat seemed like a cheesy-sounding service whose primary feature ? the ability to have photo messages disappear automatically after 10 seconds ? made it sound like nothing more than a tawdry ?sexting? app for teens.

Wondering what hours the Transportation Security Administration?s PreCheck lanes are staffed at your local airport? Or whether you can bring an obscure item through airport security?

There are several hundred thousand podcasts available through Apple's podcast app, and all of them cost the same amount: nothing.