The app has been downloaded five million times on Android before it was removed from the Google Play Store.
App-tracking platform App Annie said that ToTok was one of the most downloaded chat apps in the US last week.
Earlier, a New York Times report said that ToTok (do not confuse it with TikTok) which is billed as a secure way to chat by video or text message with friends and family is allegedly being used by the UAE government as a spying tool for mass surveillance.
ToTok "is used by the government of the United Arab Emirates to try to track every conversation, movement, relationship, appointment, sound and image of those who install it on their phones".
According to US officials familiar with the classified intelligence assessment, the app that works like Signal or Telegram has been downloaded millions of times on Android and iOS devices in the Middle East, Europe, Asia, Africa and North America.
"ToTok surged to become one of the most downloaded social apps in the United States last week, according to app rankings and research firm App Annie," the report said on Monday.
An investigation by NYT found that the firm behind ToTok is known as Breej Holding which is a front firm affiliated with DarkMatter, an Abu Dhabi-based cyberintelligence and hacking firm.
DarkMatter is already under an FBI investigation for possible cybercrimes.
The probe also linked ToTok to Pax AI, an Abu Dhabi-based data mining firm that appears to be tied to DarkMatter.
The UAE "has also been at the forefront of using surveillance technology to crack down on internal dissent including "hacking Western journalists, emptying the banking accounts of critics, and holding human rights activists in prolonged solitary confinement over Facebook posts," the report claimed.
The UAE government declined to comment on the report.
"While the existing ToTok users continue to enjoy our service without interruption, we would like to inform our new users that we are well engaged with Google and Apple to address the issue," ToTok said in a blog post.
( With inputs from IANS )