Travel Frog, or Tabi Kaeru, a Japanese mobile game about rearing a pet frog and supplying him with equipment to travel, has in recent weeks risen to become the most downloaded free game from Apple’s App Store in China. So popular is the game in China, presently the world’s largest gaming market, that there are now low-quality copycat games appearing in the App Store, as well as unauthorized assistant software that helps users cheat in the game.

China’s obsession over Travel Frog has come as a surprise to many, not least to its Japanese developers at Hit-Point, who released the similar-natured game Neko Atsume, or Kitty Collector, back in 2014. In an interview with Sina, the developers behind Travel Frog expressed that they had also been taken aback by the news of how much of a hit the game is with Chinese youths. While Travel Frog is currently only available in Japanese in App Store (an unsanctioned Chinese version of the game, however, is available in Android systems), the language barrier appears to have no effect in deterring Chinese players. According to a statement released by Hit-Point, Travel Frog has hit 10 million downloads in Apple’s App Store and Chinese users alone are responsible for 95% of the downloads. Japanese users, on the other hand, contributed only 2%.

Image credit: Hit-Point

There have been many theories about why the mobile game is so beloved in China. The cuteness of the character, the titular frog, and the interface of the game may play a significant factor. The game developers themselves have stated that when they designed the game, they had initially envisioned young females between the age of 10 and 30 as the target demographic. The fact that the game calls for less time commitment or skills from its players—most of the time when you’re playing Travel Frog, your frog is traveling and all you can do is patiently wait for him to come back home or wait to hear from him via postcards—has also set it apart from other mobile games, which are more demanding of the users’ focus and energy.

But perhaps it’s the traveling aspect of the game that has appealed the most to Chinese players. By playing Travel Frog, users are able to travel vicariously through the postcards and mementos given to them by their frogs. A Weibo user has remarked that the best part of the game is that she is able to savor a taste of freedom and wanderlust that she desires, but is unable to satisfy in real life.

The popularity of Travel Frog has, unfortunately, led to a slew of copycat games that are looking to bank on the game’s fame. Last week, a Chinese version of Travel Fog that required users to pay 30 RMB ($4.74) before downloading appeared on China’s App Store. The copycat game, developed by Song Yang, and not Hit-Point, garnered nearly 8,000 reviews, most of them from angry customers claiming they had been scammed. While the game was later removed from the store, Chinese knockoffs of Travel Frog are still prevalent. In Apple’s App Store, there currently is an app called Frog Traveling!, as well as another game that bears a similar name to the Chinese translation of “Travel Frog.” Both games unsubtly ape the design of the real Travel Frog.

In addition to the influx of copycat games, there have also been reports of illegal assistant software that is being used to help users gain more in-game currency. The longevity of software like this, however, may be short-lived, as many users are claiming that the software led to data loss and malfunctions of their phones.

According to the Hit-Point developers, they are currently working on producing an international version for Travel Frog in response to the game’s largely international user base.