SCP/Item/Feature: SCP-1590 (http://www.scp-wiki.net/scp-1590)
Explanation: SCP-1590 would be a showcase SCP functioning similarly to a combo of SCP-1499, SCP-860, and SCP-330. Players would pick up SCP-1590 in the form of a tablet, with the app (called "The Book of Tamlin") already loaded on the device. Upon using the tablet, it would load the intro screen for the player. The player then would press Start, and the tablet would run through several levels in the game (I suggest 7 for less-data-consummation purposes, as in the SCP log, that's the minimum amount a person playing the game would play before it auto-game over's). Upon finishing 7 levels or not finishing a level in the allotted time, the game will load up its end-screen, and the tablet would turn off. Any attempts by the player to replay the tablet would be met with failure. Upon playing the tablet, any door that the player opens would instead lead to a room similar to one of the rooms played on the tablet (the player would not be forced to enter the room, but at that point there isn't really a way to go BUT there). Upon entering the room, the player would walk around the room for a couple seconds, and then the player would die (cause of death being dependent on whatever the room they get sent to even is), having them respawn in whatever room they last saved.
Any other notes: The rooms design and tasks are entirely decidable by the developers: I suggest, however, that some of them have some sort of relevance to the player canonically, with the player commenting on them, as well as the room they enter in the end upon playing the game. As well, the loading screen of the game mentions the name of the last user who played the game: this, I suggest, could be an opportunity to add some sort of small name-based easter egg into the game, placing someone's name inside of that part of the SCP.