Kate was reluctant to sign up to a new app that claimed to be an investment opportunity.

But family members kept telling her how much "money" they were making from it.

"So when somebody comes to you with that type of information, you'll be like, 'Oh, man, this is true. Let me give it a shot'," she said.

The app called Hope Business asked people to pay money into an account to enable them to earn money back. It is no longer available for download.

Kate — not her real name — said the app offered financial rewards for playing games.

Things got more tempting when the app announced a 12-day promotion that rewarded people who paid or "topped up" large amounts of money into the app.

One of Kate's family members claimed to be making hundreds of dollars in commission each day.

"So this person topped up $8,000 and then I was like, 'Oh, how much are you making?'" Kate said.

"She said about $1,000 a day. I was like, really? She said yes. So I'm like, oh OK, I have to get in quick before the 12 days end."

Kate paid $7,500 to the app and started playing.

"I was getting actually good commission [of] $900 to $1,000 a day," she said.

Her balance in the app was going up but it told her she could not take money out until the end of the promised 12-day promotion.

That was not what happened when day 12 came.

"They've disappeared with the money," she said.

"That was the end for them. They've packed [up] and de-activated [the app] and shut down completely."

Kate is one of the dozens of Queenslanders who have lost a total of $466,000 on the app in just a few weeks.

That money will probably never be recovered, police say.

"I also invited my family members as well, so at least about six to seven people, you know, that I've known that have lost a lot of money," Kate said.

Detective Sergeant Karen McAteer from Queensland Police Service's Financial and Cyber Crimes Group said Hope Business was a classic pyramid scam.

"How pyramid scams work is that you have to bring more people into the scheme," she said.

"So, you not only have to invest yourself, but then you have to recruit … and the more people you recruit, it says, the more commission you will make."

Sergeant McAteer said scams involving apps were just a more modern version chain letters or Ponzi schemes.

"The first people in will get some money back … that gives them the trust to go and tell their friends and family that it's working really well," she said.

She said the pandemic had created fertile ground for scammers to target desperate people.

"They do target the most vulnerable in our society," she said.

"So, if you're already hurting, you might be looking for some sort of, I guess, side job or something that's going to make you some more money, and these things might look very attractive."

Sergeant McAteer said the apps were run by overseas criminal groups, making it hard to recover the money.

We offer tailored front pages for local audiences in each state and territory. Find out how to opt in for more Queensland news.

Read more

"It is gone very quickly, and we don't really have a lot of hope of getting any money back," she said.

She said people should see warning signs when they are being asked for money and it claims not to be a scam.

"Even if they are your trusted friends that are recruiting you, take a step back, go and seek some independent advice," she said.