AdvertisementTwitter replaces its bird logo with an X as part of Elon Musk's plan for a super appUpdated July 24, 2023Juliana KimfacebookEmailTesla CEO Elon Musk speaks during an event to launch the new Tesla Model X Crossover SUV on Sept. 2015 in Fremont, California. The billionaire has a long-time affinity for the letter "X." (Getty Images)This article was originally published on July 23, 2023.