The MushPhone is a mobile device capable of communicating over extremely long distances without the utilization of traditional signal waves. It was invented by Professor E. Gadd at the Research Center with the help of his team in the Sub-Dimensional Travel division. The firmware of the device uses a modular structure, allowing any number of applications to be installed or removed at will without affecting other software on the device.
Mario is given one of these devices before he travels to Gearonia. He uses it throughout his adventure to receive communications from those at the Research Center and others he meets over the course of his travels. The device is also being used by others in Gearonia that are involved in efforts to quell the Umbral Deluge.
Functionality
The device communication functions by transporting its data into sub-dimensional space before sending it in the relative direction of the receiver. After reaching the receiver, it will flip back into the correct dimension and deliver the data contained in the communication. Because the technology is designed in this way, it also allows for inter-dimensional communication. The sub-dimensional space acts as a "hub" where data can travel between multiple dimensions.
Even though the MushPhone avoids many of the pitfalls of potential wave-style signals, sub-dimensional communication still has its weaknesses. Most notably, if any other form of matter happens to be traveling within the same section of subspace at the same time, there is a possibility for collision. Collisions can garble the data being sent or dismantle it altogether, meaning it will never reach its receiver in an intelligible state.
Collisions are almost guaranteed when attempting to use the MushPhone in areas heavily affected by the Umbral Deluge. The corruption is so potent that it has begun to bleed into sub-space, a phenomenon that is particular evident in Withering Wasteland.
Applications
The MushPhone supports a variety of applications, all of which are designed and implemented by a team at the Research Center. Some apps can even be upgraded, adding new features on top of the base functionality.
Messages
Because of the MushPhone's unique communication framework, this app is largely considered the device's flagship application. Its functionality is simple. Users can send and receive direct messages. Images and text effects are supported. Users can also sort & filter their message list by various parameters.
Escape!
Using the technology of E-Gates↗ that assisted Luigi in his quest to collect the shards of the Dark Moon↗, the Escape! app allows the user to instantly transport their physical body to numerous predetermined waypoints around the world. The core intention behind the application is user safety and convenience. They are expected to use its features to escape dangerous situations or reduce travel time between areas of the world.
Inventory
Utilizing the MushPhone's spatial analysis sensors, the device can detect and store which items are currently being carried on a user's person. It also has the capability to store digital goods, such as currency or vouchers. The Inventory app provides a centralized location for user's to view details about item's they are currently carrying, as well as equip/unequip wearable gear and accessories.
Adventure Log
The Adventure Log app is a highly capable note-taking utility geared towards travelers, nomads, and other adventuring types. It automatically categorizes and summarizes quests and objectives encountered throughout the user's travels. The summaries include the events that occurred up until the current point, as well as the next steps that the user may take to further advance their adventure.
Progress
The Progress app systematically scans the user's current region for treasure and other goodies. It builds a database of these items and tracks whether or not they have been collected by the user. This is useful for adventurers who want scour every inch of the land to obtain as much treasure and notoriety as possible.
The app can additionally be upgraded to track a wider variety of goodies and treasure.
Milestones
The Milestones app acts as a personal achievement tracker for the user. It automatically analyzes the nature and contents of a user's adventure and creates curated goals and challenges for them to complete. It is even capable of automatically detecting when a milestone has been reached and marks it as completed within the app.
The app can additionally be upgraded to unlock an additional category of Milestones that are particularly difficult or cryptic to reach.
Stats
Much like the Milestones app, the Stats app curates personal data for the user, but instead of tracking concrete goals, it simply keeps record of various statistics that relate closely to the user's habits. It may track the number of times they've jumped, how many injuries they've sustained, or even records from sports and games.
Music Player
The Music Player app's functionality is largely in the name. It gives the user the capability to play music through the MushPhone's speakers. One unique feature of the app, however, is its ability to automatically capture and store music that is picked up by the device's microphone. This allows users to listen to tunes they've encountered throughout their adventure as often as they'd like.
Costumes
Using an illusionary technology harnessed from ghosts, the Costumes app allows the user to alter their outward appearance without the use of physical clothing, accessories, or cosmetics. The base version of the app allows the user to change their outfit.
The app can additionally be upgraded to unlock the ability to add complementary visual effects like sparkles, glows, and movement trails.
Device
The Device app uses the same technology as the Costumes app to instead alter the outward appearance of the MushPhone itself. It can change the color and texture of the device and even add small accents or accessories to the surface.
The app can additionally be upgraded to unlock the ability to edit each component of the device individually, rather than applying one customization scheme to the entire device.
Wallpapers
Arguably the most simple of them all, the Wallpapers app allows the user to change the background that is displayed while using the MushPhone.
Stickers
Once again using the illusionary technology seen in the Costumes and Device apps, the Stickers app allows the user to place digital stickers almost anywhere on the surface of the device. New stickers can be unlocked via a direct integration with the Milestones app. The more Milestones a user reaches, the more stickers they can use to customize their device.