Since launching in 2012, the venture now boasts a user base of 1.5 million and remains focused on the Australian and U.S. markets. “New millennial parents love the fact that they know where the data is going and who gets to see it,” Geller noted.

The family-friendly app debuted on Australia’s stock exchange Friday after raising 6.5 million Australian dollars ($4.9 million), but the stock ended up closing below its 1 Australian dollar issue price at 95 Australian cents.

A mobile app and a website, Tinybeans is free to download but it also boasts a premium version with additional features, including a paid service to create photo books.

Subscriber growth has been growing year-on-year over the past four years, according to Geller. “Most of it is word of mouth, and most of it is organic. Our most passionate users are using us almost every day,” he said.

In fact, some users are so bullish on Tinybeans that they’ve become investors.

“Over the last couple of years, we’ve had many of our users reach out and want to contribute and be part of the business,” Geller said.