Finding the right bra size can be frustratingly difficult. Your chest is either spilling over the top of the neckline, or it’s slightly shallow, leaving room for a sizable gap in the cup (sometimes big enough for wallet-size storage).

Fed up with how time-consuming bra shopping (and sizing) can be, Heidi Zak decided to streamline the process into one highly interactive, easy-to-use app called ThirdLove, named after what she says are the three qualities a woman looks for in an item of clothing: style, feel, and fit. “I wanted to use technology to bring the process of shopping for a bra into a woman’s home,” Zak told InStyle.com of her new venture. “It should be fun to get fitted—it shouldn’t be something you dread.”

The way ThirdLove works is simple: Simply open the app’s sizing tool, strap on a supportive bra under a tight-fitting tank, stand in front of a wall-mounted mirror, and snap two selfies with your iPhone—one from the front and one from the side. A Siri-like virtual fit assistant will guide you through each step, advising you to adjust the tilt of your phone toward or away from the mirror to position the shot. The app will then generate your unique ThirdLove size, which factors in the overbust and underbust and even includes handy half cup sizing for the in-betweeners.

Once you’re measured, with the swift swipe of a finger you can jump to ThirdLove’s e-commerce store, where your shopping experience is personalized to your size and liking. You can pick and choose different colored straps, bows, and lace to customize your new bra, and even tack on a pair of matching skivvies to boot. Prices for the bras range from $39 for a microfiber bra to $64 for a lace bra, and each comes equipped with a foam pocket closure on the back, as well as tagless printing—so you don’t have to worry about any pesky itching at the closure. What’s more, each model that you see wearing the bra on the product page is closely related to the size of your body (so if you’re a C cup, you’re not going to be shown a model who’s an A cup).

According to Zak’s research, a woman changes bras six times over the course of her life. Next time, we suggest cutting out the middle man.

Download ThirdLove for free on an iPhone from the iTunes app store or head to ThirdLove.com to shop bra styles.