Remember when your cellphone bill was $30–$40 a month? If you do, you probably weren’t using a smartphone. It’s no surprise that our phone bills have increasingly become more expensive over the past decade. Today, you can’t really own a smartphone unless you’re willing to shell out at least $70 a month. And even then, it usually means that you’re making some sacrifices to your data plan, your minutes, or your text messages. I wanted to figure out how to own a smartphone, and pay as little as possible to use it without worrying about overages. After digging around I figured out a way that costs only $30 and gives me unlimited everything. Yes, that’s right. Unlimited talk, text, and data. How did I do it? Read on and find out. Here’s what you’re going to need: T-Mobile prepaid plan, Google Voice and Talk-a-tone app.