Nitrome Ltd.

Background
Founded in 2004, Nitrome Ltd. is a browser game developer based in London. They also make mobile games. You can view their website here. In 2018, their game Bomb Chicken was released on mobile and the Nintendo Switch (ultimately a huge milestone for the company). Their very first game, Four Play (which is also their first mobile game), was released on August 7, 2005 as a test game for mobile phones. Their first browser game, Hot Air, was released on December 6, 2005.

(August 7, 2005-)
Logo: The animation varies depending on the game, but the final result is the word "nitrome" (in a blocky font) tilted at an angle. Copyright info is also below.

FX/SFX: Depends on the game.

Variants:
 * You can see the custom variants here.
 * Sometimes, copyright info is not below.

Music/Sounds: Sound effects depending on the game, followed by a dreamy, retro-sounding synth chord.

Availability: First seen on Four Playand appears on all of the company's games.