Mr Nazarovas said the discovery of unprotected sensitive material comes with a significant risk for the platforms' users.
Malicious hackers could have found the images and extorted individuals.
There is also a risk to those who live in countries hostile to LGBT people.
None of the text content of private messages was found to be stored in this way and the images are not labelled with user names or real names, which would make crafting targeted attacks at users more complex.
In an email M.A.D Mobile said it was grateful to the researcher for uncovering the vulnerability in the apps to prevent a data breach from occurring.
But there's no guarantee that Mr Nazarovas was the only hacker to have found the image stash.
"We appreciate their work and have already taken the necessary steps to address the issue," a M.A.D Mobile spokesperson said. "An additional update for the apps will be released on the App Store in the coming days."
The company did not respond to further questions about where the company is based and why it took months to address the issue after multiple warnings from researchers.
Usually security researchers wait until a vulnerability is fixed before publishing an online report, in case it puts users at further risk of attack.
But Mr Nazarovas and his team decided to raise the alarm on Thursday while the issue was still live as they were concerned the company was not doing anything to fix it.
"It's always a difficult decision but we think the public need to know to protect themselves," he said.
In 2015 malicious hackers stole a large amount of customer data about users of Ashley Madison, a dating website for married people who wish to cheat on their spouse.
