The daily struggle of figuring out what to wear may finally be over.

According to former broadcast journalist Whitney Casey, "Eighty percent of your clothes, you aren't wearing. That's half a trillion dollars just hanging there."

This realization led her and model turned actress Brooklyn Decker to launch the Finery app in 2017. The free app helps users manage their wardrobe virtually and acts as a personal stylist, creating new looks based on the clothes you already have.

The company made this year's CNBC Upstart 100, an exclusive list of promising young start-ups, featuring a diverse group of companies that are building brands and breaking industry barriers on the path to becoming tomorrow's household names.

"What's great is we style you. A woman will spend eight years of her life shopping and two getting dressed. We're shaving the time off that," Casey said Tuesday on CNBC's "Power Lunch."

Finery gathers users' purchase information by filtering through their email and browsing history. "We find all of your purchases — from your e-receipts, from your browser history, from attaching your accounts — and then we instantly upload all of those items into a virtual closet so you see what you own." The CEO added that Finery goes back "10 years into your purchase history."

Finery's algorithms can also use your purchase history and style-quiz answers to find gaps in your wardrobe and suggest items from more than 10,000 stores with which Finery has a relationship. The company also features a blog with videos, articles and examples of styles and uses images from over 1.5 million blogs to influence and create "trends."

Casey claims the company currently has hundreds of thousands of users, but "the bigger picture of this," she said, "is about data. That is the ethos. Women need to have data working for them, and it is very hard to get data from them."