or other content through the app and resubmitted it for approval in June 2018, where it was accepted by Apple and allowed on their store in May 2019. Steam-branded devices Prior to 2013, industry analysts believed that Valve was developing hardware and tuning features of Steam with apparent use on its own hardware. These computers were pre-emptively dubbed as "Steam Boxes" by the gaming community and expected to be a dedicated machine focused upon Steam functionality and maintaining the core functionality of a traditional video game console. In September 2013, Valve unveiled SteamOS, a custom Linux-based operating system they had developed specifically aimed for running Steam and games, and the final concept of the Steam Machine hardware. Unlike other consoles, the Steam Machine does not have set hardware; its technology is implemented at the discretion of the manufacturer and is fully customizable, much like a personal computer. In 2018 the Steam Machines were removed from the storefront due to low sales and small user traffic. In November 2015, Valve released the set-top box Steam Link and Steam Controller (which was discontinued in 2019). The Steam Link removed the need for HDMI cables for displaying a PC's screen and allowed for wireless connection when connecting to a TV. That was discontinued in 2018, but now "Steam Link" refers to the Remote Play mobile app that allows users to stream content, such as games, from a PC to a mobile device over a network. Valve released the Steam Deck, a handheld gaming computer running an updated version of SteamOS, with initial shipments starting on February 25, 2022. The Deck is designed for the play of Steam games, but can be placed into a separate dock, purchased separately, that allows the Deck to output to an external display and use the dock's power, networking, and connected USB accessories. The Deck was released on February 25, 2022. Among updates to Steam and SteamOS included better Proton layer support for Windows-based games, improved user interface features in the Steam client for the Steam Deck display, and adding Dynamic Cloud Saves to Steam to allow synchronizing saved games while a game is being played. Valve began marking all games on the service through a Steam Deck Validated program to indicate how compatible they were with the Steam Deck software. Chromebooks In March 2022, Google offered a prerelease version of Steam on Chromebooks, and entered public beta