Musi, a company developing the eponymous YouTube streaming app, is suing Apple because the software that has 66 million users was removed from the App Store.

According to the filing submitted to the US District Court of Northern District of California, Apple did this based on an “unsubstantiated third party complaint,” thus violating the contractual agreements it has with Musi.

We obtained a copy of the lawsuit for you here.

The proper course of action, the company states in the lawsuit, would have been for Apple to “investigate in good faith,” instead of simply kicking the app from the store. The third-party complaint has to do with suspected infringement of YouTube intellectual property.

Musi also claims that all it took for Apple to make the drastic move was YouTube’s complaint consisting of only five words – namely, that its terms of service had been violated. As is YouTube’s habit, no further explanation was attached to the accusation.

But, Musi’s lawsuit said, YouTube did go to the trouble of “lying to Apple” when they said Musi failed to respond to the video platform’s attempt to settle the issue before involving Apple.

Musi launched in 2016 and claims to have always responded to YouTube, either by answering questions, letting the giant know how the app functions, or making changes to it. For that reason, the complaint insists that Musi was fully complying with YouTube’s ToS.

Musi was only available for iPhones and consequently only on the App Store. The app is free while displaying Musi’s own ads is the business model. The content it provides to users is publicly available.

Before the YouTube accusation that got it removed from the Apple store, some have questioned whether artists were getting a cut from Musi’s revenues (the company has maintained that they do), and also, if its own interface was used instead of the YouTube API was in line with the terms of service.

To that, the answer has been that YouTube videos are not stored, processed, or transmitted by the app and that it works by playing and displaying content “based on the user’s own interactions with YouTube and enhances the user experience via Musi’s proprietary technology.”

Given the lack of any explanation from YouTube, it is believed that the reason Musi was reported to Apple lies there, prompting the giant to act “abruptly and arbitrarily.”