YouTube

Background
YouTube is an online video sharing and social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chan, Chad Hurley, and Jawed Karim. It has been owned by Google since 2006, and is the world's second most visited website, after Google Search. As of January 2023, there have been over 2.51 billion monthly active users on the platform, with more than one billion hours of videos being watched every day.

1st Screen (2012?-2014?)
Visuals: Just the YouTube logo from the time (with a rounded rectangle behind the "Impact") glowing against an almost black gradient background.

Variant: From 2013, both the background and the logo are in their solid colors, and the glow on the logo was removed. The background is also.

Technique: None.

Audio: None.

Availability: Seen when you open the versions from 2012 to 2014 of the YouTube app on an iPhone.

2nd Screen (2014?-)
Visuals: There is the YouTube play icon (a rounded rectangle with a white triangle at the center) on a white (if the device is on light mode) or  (if the device is on dark mode) background. The rectangle then turns and into a streak as the triangle moves to the left (and turns black if the device is on light mode). The streak turns depending on the amount of seconds, and deforms as the triangle moves to the center of the screen to cut to the UI.

Variants:
 * Originally, the logo was still and had a shadow inside the triangle, and the 2013 Google logo in was at the bottom of the screen.
 * The Google logo would eventually be removed sometime around late 2015.
 * The shadow inside the triangle would be removed in 2017.
 * When v16.45.32 of the app was released in 2022, the rectangle started off as, and quickly turned red as the white triangle pops up from its left.

Technique: 2D computer animation. None for the earlier variants.

Audio: None.

Availability: Seen when you open the YouTube app on a tablet or a phone.