The mobile version of Fortnite is currently available on iOS as invite-only, and yet despite this limited availability, the game has successfully risen to the top of the App Store charts around the world. While this may be surprising to some given that the floodgates have not yet fully opened to let players into the game, more impressive is the news that Fortnite iOS has already made millions of dollars.

According to app data and intelligence firm Sensor Tower, which cites data from its Store Intelligence platform, the iOS version of Fortnite has already made over $1.5 million in just four days. The firm says that $1 million of this figure was made during the first 72 hours of the game's availability on iOS devices. The game makes money by selling cosmetic skins for a premium currency which can be purchased with real money.

Fortnite's huge amount of revenue also vastly outpaces other battle royale games available on iOS, including NetEase's gritty battle royale game Knives Out (it made $57,000 in its first four days) and Rules of Survival, another NetEase battle royale game that has 150 million players worldwide (it made $39,000 in its first four days).

Fortnite iOS revenue data graph

Sensor Tower's report also notes that Fortnite iOS is also doing quite well in comparison to other major mobile hits of the past few years. For example, Pokemon GO made $4.9 million in its first four days while Clash Royale made $4.6 million in its first four days of availability on iOS and Fortnite has made about a third of that so far. Given that Fortnite is not yet available in full and it is a lesser-known IP than the likes of Pokemon and Clash Royale (Clash Royale is a spin-off of the mega-popular Clash of Clans), those stats are all the more impressive. Pokemon GO has gone on to make more than $1 billion and some will be wondering whether Fortnite iOS can eventually reach that figure too.

Fortnite is off to a white-hot start on iOS but the game still has a lot of growing to do. Not only will developers Epic Games and People Can Fly remove the invite barrier and let everyone play the game, but Fortnite is also planned to launch on Android devices at a later date too. That $1.5 million figure could just be the start for this potentially very successful mobile spin-off.

Fortnite is available now in early access for iOS, PC, PlayStation 4, and Xbox One, with Android support coming later in 2018. Source: Sensor Tower