Free games can make a lot of money.

Bethesda's popular free-to-play mobile title Fallout Shelter has now brought in more than $90 million from its microtransactions across iOS and Google Play, according to a new report. Research company SensorTower (via Gamasutra) says the first Fallout mobile game has now made $93 million from the sale of its "lunch boxes" and other items that players can buy with real money.

The firm also stated that Fallout Shelter microtransaction revenue was around $212,000 on June 15 this year, which marks the highest single-day since September 14, 2015 (~$237,000). The revenue was almost evenly distributed between iOS (49%) and Google Play (51%). It was also estimated that 59 percent of Fallout Shelter's revenue has come from the US.

If Fallout Shelter can hold its current revenue patterns, it could reach $100 million by the end of the year. The game reached 100 million downloads in September of last year.

The $93 million revenue figure only applies to Fallout Shelter's iOS and Android versions. The game is also available on PC, Xbox One, Nintendo Switch, and PlayStation 4, so the title has surely made much more than $93 million when all platforms are combined.

Given the immense popularity and profitability of Fallout Shelter, it makes sense that Bethesda is continuing down the mobile game path with The Elder Scrolls: Blades later this year. While details have not yet been announced, the game is likely to have microtransactions in some form. For more on Blades, you can check out GameSpot's interview with Todd Howard.

In other news, Bethesda parent company ZeniMax is currently suing Warner Bros. over claims that the new Westworld mobile game is a ripoff of Fallout Shelter.