Apple has created "mockups" of its iMessage app for Android, suggesting that the company has seriously considered at some point porting the service to non-Apple products.

"I’ve heard from little birdies that mockups of iMessage for Android have circulated within the company, with varying UI styles ranging from looking like the iOS Messages app to pure Material Design," Apple-focused writer John Gruber wrote on Monday.

Material Design is the official design language Google's apps use.

"Messages for Android may never see the light of day, but the existence of detailed mockups strongly suggests that there’s no 'of course not' to it," he continued.

iMessage is one of Apple's most important services. For many people, messages are the most used app on their phone. The genius to Apple's "hidden social network" is that it replaces the text app: if you're texting someone who has an iPhone, it automatically turns into an iMessage, and turns the message from a green text bubble into a blue text bubble.

There are countless stories of people who have switched to Apple products exclusively so that they can join iMessage groups or send blue bubbles.

And in the recent update to iOS, Apple spent a lot of time improving the iMessage experience, adding new stickers, apps, and features.

iMessage only runs on Apple products, including the iPhone, iPad, and Mac, and an Android port been rumored several times in the past. Apple doesn't make many Android apps; Apple Music is the most notable.

But an Android version of iMessage still doesn't made sense — Apple makes the vast majority of its money when people buy its products. iMessage is a strong reason to continue buying those products. There are also security implications if iMessage were to run on Android, given that the system uses Apple hardware to help its encryption.

As a "senior executive" told the Verge earlier this year:

When I asked a senior Apple executive why iMessage wasn’t being expanded to other platforms, he gave two answers. First, he said, Apple considers its own user base of 1 billion active devices to provide a large enough data set for any possible AI learning the company is working on. And, second, having a superior messaging platform that only worked on Apple devices would help sales of those devices — the company’s classic (and successful) rationale for years.

Still, it sounds like Apple assigned someone internally to answer the question: If iMessage was ported to Android, what would it look like?