Now that Fortnite is back on iOS with Apple's approval of the game, Microsoft is jumping in to try to extend its ability to sell games on the platform through its Xbox app.Microsoft on Tuesday filed an amicus brief in district court in support of Fortnite publisher Epic Games saying that Apple has "stymied" its efforts to sell games through its mobile Xbox app on iOS.

Fortnite returns to the US App Store after a five-year legal clash with Apple, a 'priceless' win for Epic Games.

The court ruling makes it possible for Microsoft to now launch its Xbox mobile store, but it’s clear that the software giant also wants to ensure Apple’s appeal against the ruling isn’t successful. If Microsoft did launch its Xbox mobile store and then Apple won a temporary stay, it may have to pull that store pending the appeal process.