Musk had complained about Apple on Twitter this week, when he claimed Apple had threatened to boot the app from the App Store without explaining why. He also complained that Apple had pulled most of its advertising from Twitter, and questioned whether Apple "hated free speech in America".
However, the meeting with Tim Cook seems to have defused the situation.
"Good conversation. Among other things, we resolved the misunderstanding about Twitter potentially being removed from the App Store. Tim was clear that Apple never considered doing so," wrote Musk.
It was not immediately clear from the tweet how this 'misunderstanding' had occurred. Tim Cook hasn't yet tweeted about the meeting.
That Apple didn't, according to Musk, consider booting Twitter from the App Store doesn't mean Apple wouldn't remove or block Twitter updates from the App Store if the social media company violated Apple's developer guidelines for the store. Cook has previously said Apple expects Twitter, under Musk, to continue moderating content. Musk, however has fired many of the employees responsible for moderating content on Twitter while its head of safety, Yoel Roth, resigned last month.
Musk also is not a fan of Apple's commissions on app and in-app purchases of 15% to 30%, which is an issue for the entrepreneur as he ramps up Twitter Blue's $8 a month fee for the verified checkmark.
Musk has suggested Apple was behaving like a monopolist, adding to the chorus of criticism about its gatekeeper role on iPhones from the likes of Epic Games, Meta and more.
Indeed, via Axios, Meta chief Mark Zuckerberg on Wednesday said at a conference that it was "problematic that one company controls what happens on the device" when discussing Apple.
Zuckerberg said that rivals to Apple being forced to exclusively deliver iPhone apps through Apple's platform was a "conflict of interest" and that Apple was not just a "governor" looking out for people's best interests.
Meta's advertising revenues have of course been impacted heavily by changes to Apple's app-tracking policies.
Zuckerberg also appeared to welcome Musk's entry into the debate about Apple and the App Store.
Musk for his part seemed chuffed at being invited by Cook for a stroll around Apple's "beautiful" headquarters.
Musk today said Twitter was addressing the bot problem that he said the platform had prior to completing his $44 billion acquisition of Twitter in late October. Recently, Musk has boasted that Twitter's daily active user numbers have reached record levels. But he warned that some users may now see their follower numbers decline.
"Twitter is purging a lot of spam/scam accounts right now, so you may see your follower count drop," he wrote.
Twitter on Wednesday published a blog explaining the drastic and rapid changes the company has undergone since Musk took the helm. Those changes, according to Twitter, are leading towards Musk's vision for Twitter 2.0.
"Twitter is embracing public testing," the company said. "We believe that this open and transparent approach to innovation is healthy, as it enables us to move faster and gather user feedback in real-time. We believe that a service of this importance will benefit from feedback at scale, and that there is value in being open about our experiments and what we are learning."