One Friday night, Elva Carri wanted to go out dancing, but her friends were all too busy.
So the Dublin resident changed her gender on dating app Tinder to male and explained in her profile that she was looking for platonic female friends to hang out with.
"That evening I just chatted to a bunch of girls on Tinder," Carri, 33, told CNNMoney. She matched with more than 100 women in just 24 hours.
The following night, she and a friend from university went out with one of her matches and had a great time.
That experience back in 2014 inspired her to start GirlCrew, an online platform that helps women forge new friendships.
GirlCrew is now available in 35 cities worldwide and has nearly 40,000 users.
GirlCrew began as a meet-up group on Facebook. Carri added her new matches on Tinder to the group so they could "hang out and connect easily."
One of those women, Aine Mulloy, started working with her on the project alongside Pamela Newenham, whom Carri met "on a surf weekend for entrepreneurs." The Facebook group went beyond Dublin and launched in other cities.
"People had requested we start them in other places," Carri said, so the team added cities where there was demand or where they thought the group would work well.
Soon they realized they needed their own app. The Facebook group was already making money through ads, partnerships and sponsorships with brands, according to Carri, but the team wanted more control.
"When you're running something on someone else's platform, you come up against limitations," she said.
In 2016, the three women quit their jobs to work full time on GirlCrew. Carri was a digital marketing consultant, Newenham was a journalist, and Mulloy worked at an educational publishing company.
In June 2017, GirlCrew launched an app in Ireland -- followed by Australia, the United Kingdom and the United States over the following year.
The app, which is free to join and use, allows users to select the city they're based in. They can join events in the local area or create their own. Members must be over 18 and sign up using their real names.
In Dublin, where GirlCrew is based, there's a premium version for $12 a month. In July this year, GirlCrew also launched a premium version in San Francisco, available for $20 a month. Premium members get access to events hosted by GirlCrew, private chat groups and discounts from businesses.
The company has raised just under $1 million in funding, and investors include LinkedIn CEO Jeff Weiner. Newenham interviewed him for an article for the Irish Times, and he wanted to invest after she told him about GirlCrew.
The business hired its first employee in 2016 and now has six of them.
Most of the app's users are in their mid-20s to mid-30s, according to Carri. They include women whose friends have moved away or had children -- as well as mothers and retirees.
"Our members are ambitious and driven, and work really hard and are passionate about what they do -- so then when they have free time, they just want to make the most of it with some other women," Carri said.
"It's not that they don't have friends -- it's just everyone is so busy all the time, we need to optimize the time we do have."