Special Uses for Informational Accessories
I'm sure most of us have at least tried to grind for the cell phone (curse you lost girl!). The thing is, a lot of those items have more uses, or at least could have more uses irl. Example, playing games on your phone... "completely irrelevant". This suggestion is about those special uses for informational accessories. Let's just go top down for now. NOTE: I realize all of this is technically "optional" those marked so are simply a small priority/wouldn't contribute too much to the suggestion.Cell Phone/PDA
The only item to bring non-informational item into the tree. On right click, the cell phone would bring up a GUI with a power button in the top-right to close it, and a home button at the bottom for teleportation if you want to do it the long way around. All of the other devices (with special features) would have an app on the phone to bring up their special feature menu. In addition, terraria's camera and housing query options would be available here (PDA would also have housing query) as well as a few games (and possibly paid apps for a tad bit more function) which will be discussed below. The PDA would be similar, but with the power button where the home button would be on the cell phone. each app in a lower gui than the main item would have a back arrow in the top-left to return to a higher device. this applies to all compound informational items.GPS
The GPS would have a "waypoint" functionality in addition to alarm functionality. The GUI would appear to be the GPS item blown up, but with the screen replaced with the terraria map, and a digital clock in the top-right which would bring up the pocket-watch's alarm functionality when clicked. There would be a green + button and a red - button in the bottom-left with a yellow eye button, and blue paper & pencil button next to them. The green + would always be lit up, but the other 3 would be dim unless you had a waypoint selected. When you click the green + it would make a new waypoint where you stand with the name "Waypoint #" with # being the number waypoint created. These waypoints would appear as little rhombi covering 4 blocks where your head and torso had been. They would act as a stationary player on your team, displaying the waypoint name, and distance to them similar to a teammate in multiplayer. After creating a waypoint, if you select it in the GPS you can delete it using the -, make it invisible in-world with the eye (toggle), or rename it with the paper & pencil.Pocket Watch
The pocket watch would have an "alarm" function. On right click it would bring up a large analog clock face (digital for compound item) with 1, 2, or 3 buttons on the side based on tier. (copper/tin, silver/tungsten, gold/platinum) when one of those buttons is pressed it will become indented and you will be able to move the hands to when the alarm should sound then click the button again to set the alarm (double click button to clear any alarm there, it will have a red wire knob on the end if there is an alarm). (click the center of the face to change AM/PM, AM is a sun for the center, PM is a moon) in a copper/tin watch it will simply say "ding!" at specified time (in chat and sound), in a higher tier watch you can configure number of chimes that will sound, and with a digital watch it will prompt for message to be displayed (it would still just play a ding sound). Optional: Add a digital watch. It would have a digital display, would have customizable alarm messages, and would be crafted with gold or platinum and 5 wire replacing a chain.
Fish Finder
Being a fish finder, the fish finder would be conveniently able to find fish for you... kinda, don't worry, sonar potions aren't obsolete. It would bring up a digital version of "Fisherman's Pocket Guide"'s ability, and in addition would have a magnifying glass next to each fish which, when clicked, would bring up the map and evaluate discovered bodies of water to see in which one's the fish would be found, displaying the fish's texture on those water bodies, with size based on catch rate (some biomes/depths have more varieties of fish, and size of bodies of water can play into fishing power), which would be displayed as percent when hovered over. Additionally it would have an "evaluate lake" option which could be used to return size and fishing power modifier for a body of water/lava/honey similar to how you can inquiry the suitability of a house.Fisherman's Pocket Guide
The fisherman's pocket guide would contain valuable information about fishing, and fish in general. It would have a book-like GUI with a page for each type of fish including the biome(s) it can be found in, whether it is hardmode or not, depth(s) it can be found in, and type of fluid it is found in. Additionally, it would have a page for times and what the fishing power effect is during those times. If used in conjunction to a pocket watch or compound device including a watch it will display fishing power effect along with time if total fishing power is displayed.Goblin Tech
To my knowledge this is simply miscellaneous tech plopped on a key ring, and as such would have no special features.Metal Detector
(Credit, the metal detector idea is not my own, and full credit, as well as the concept of improving info items that sparked these ideas are owed to that thread) On right click, the metal detector would open up a GUI displaying something like the metal detector held horizontally. The main part of the detector would be replaced with a (scrolling? based on length) list of items that the detector can detect along with their item weight in the detector. You would then be able to edit these values to change which block will override which when detected. (If you really want copper in a world you've mined most of it out of just quick give it a weight of 1000 and then iron (or anything else) won't override it. On a more serious note, if you made it to plantera without 400 life you could set life crystals above life fruit, or if you don't care about pots you could give them a weight of 0 (to not show up at all?))Stopwatch
It's a stopwatch, and should be able to be used as such. On left click it will simply start/stop the timer which will be displayed in info if it is not 0, and on right click it will reset time to 0.R.E.K. 3000
The R.E.K. 3000 would be able to be configured to filter out certain enemies as "rares" even if they are not rare, and display how many of those are nearby, with the normal count not counting those and displaying as "other enemies/critters nearby" rather than "enemies/critters nearby".Radar
The radar would be configurable to display "enemies", "non-townsfolk/player lifeforms", or "critters". The display would update accordingly, displaying nearby enemies, critters, or both combined to say "lifeforms".Tally Counter
Stats can be interesting, and fun to compare with friends at times. The tally counter will allow this to a fuller extent. On right click it will bring up a rolling number display with 3 numbers as well as a dropdown in the top-left. This dropdown will contain "<mob> kills", "deaths", "total kills", "days so far", "damage taken", "damage dealt", etc. each would display their specified number when selected ("<mob> kills" bringing up a mob selection window first). Should the number be above 999 (the max number displayable in base 10 on a 3-number display) it will play a boing noise, and a spring will pop out of the right side at the end of which would be a tag showing the actual number (in scientific notation to fit if required)(Optional) Games
These would be a feature in terraria that serve no real purpose. When you right click the cell phone a few games would be available with the useful apps. Similar to those in scribblenauts these would be mildly entertaining, but rather pointless arcade games.Worm/Nightcrawler/Spelunker
A triad of games contained within the "worm" game app. These would be based on the classic "Snake" arcade-style game. In each game the player would be a worm/enchanted nightcrawler/golden worm searching for food to help you grow in length (apple (using wormy apple sprite?)/blessed apple/gold ore). you start at a length of 2, and go around in a 2d top-down boxed-in world waiting for your respective food to spawn. The more food you eat, the greater your score is. If you hit your tail or the side however, it's game over.Pak-Slime
Pac-man, but rather than the yellow maw you control a little slime, common variant of your choice. Your goal is to absorb as many coins as possible in the maze (coppers or silvers for the little dots, platinums for the super dots), and avoid the zombies (ghosts: Inky, Blinky, Winky?, and Clyde). After absorbing a platinum you temporarily become pinky, a faster variant capable of absorbing the zombies in addition to the coins. In order to advance through each level you must consume all of the coins. Fewer and fewer coins will be replaced by platinums, pinky will last for a shorter amount of time, and zombies will get faster as the levels go on.Pong
Pong. You select an opponent (NPC/Player) after selecting the app, and then play (the player gets a game invite which can be accepted/declined. If declined there is a 30sec wait to avoid spam). The AI for each NPC may vary slightly, with cosmetic changes to the opposing paddle based on who you're facing (witch doctor gets leaves, steampunk gets gears, etc.) You use w/s to control your paddle (there is one at each end of the screen), and try to prevent the ball from getting past you while hoping it passes your opponent. Configurable game win score requested on game start."Paid" Apps
In addition to all those wonderful options there would be a few "paid" apps (paid in coins of course, not real cash). These would affect the world a bit more than others, but as stated, come at a cost.Uber
The classic taxi app, this will allow you to teleport to any waypoint stored in the phone as if it were truly another player on your team (or you're spawn point, or teleporters were connecting it to you, etc.) for a fee of 15 coppers per block. Wormhole potions count as probably about 1/4 or 1/8 map width. with options of "use wormhole", "use wormhole efficiently" (supplementing a not entirely used wormhole potion with money), or "cash only"Loot Crate
An app that will slowly leech away your cash when enabled... loot crate will give you random loot each day normally found in chests or as uncommon (but not too important) drops from enemies. it will charge the player 2 golds a day, and will not return coins in the crate.Feel free to suggest more features for informational items or apps for the cell phone in the comments, constructive criticism welcome.