In Letterpress, two players compete to claim the most tiles on a grid of 25 random letters. Players must assemble a valid word; they cannot reuse words, use words not listed in the game's dictionary, or use words from the same word family. When a player finishes their turn, their selected letters change to their color. If a player's tiles surround a letter they have claimed, the opponent cannot claim it, though it can still be used to create words. To indicate this, the surrounded tile becomes a different shade. A locked tile loses its status if an opponent claims tiles in proximity. Players may choose to pass a turn. Once every square is colored, or if both players pass their turns in the same round, the player who owns the most tiles wins. In single-player mode, the second player is replaced by a bot.

After leaving Twitter, Inc. in November 2011, Loren Brichter, the founder of Atebits 2.0, began finishing side projects he had previously had little time to work on. Along with his experience as a graphics engineer for the original iPhone, he had previously created Tweetie and the pull-to-refresh function. Brichter saw Letterpress as a way to experiment with new Apple software. After playing Zach Gage's single-player iOS game SpellTower next to his wife, Jean Whitehead, he was inspired to develop a multiplayer word game they could play together. Focused on combining color and words, Brichter cited Boggle and color wars as influences for the gameplay.

Whitehead was the first beta tester and helped refine the game's rules. In the first version of Letterpress, players could freely create long words, as tiles would only be colored instead of locked. He incorporated a feature that gave players bonus points for claiming tiles that have been surrounded. However, Brichter realized that games would be endless due to players avoiding the remaining tiles; to fix this, he made surrounded tiles unclaimable. For graphics and the user interface, he took inspiration from the Windows Phone. The game was written in OpenGL, and Game Center, Apple's multiplayer networking service, handled multiplayer matchmaking. Brichter created most of the sound effects himself by spitting and making other noises with his mouth into a microphone. He determined the game's name based on what the player did: pressing letters, which Brichter felt it alluded to letterpress printing.

The game was released for iOS on October 24, 2012, and on that day, it was downloaded over 60,000 times. By November 2012, the game had garnered one million downloads. In December 2012, Letterpress was updated with a replay feature that shows each individual turn in a game. After Solebon LLC acquired Atebits 2.0, the game was released on the Mac App Store on July 20, 2016, and on Google Play on August 25, 2017.

Brichter marketed Letterpress as freemium. In the free version, players could only compete in two games at once, while the premium version allowed unlimited games, the ability to see previously played words, and more themes.

Letterpress has a "generally favorable" Metacritic rating based on eight critics. It was featured in the App Store's Best of 2012 list, ranking second place as the game of the year for iPhone. It was nominated at the Worldwide Developers Conference and won the 2013 Apple Design Awards.

Reviewers found the strategic elements of Letterpress engaging, comparing it to Scrabble, Reversi, Connect Four, Go, SpellTower, Words With Friends, and chess. Despite Jared Nelson from TouchArcade finding the gameplay challenging to articulate, he noted its addictive nature once players understood the rules. Lex Friedman from Macworld described it as "addictive", while AJ Dellinger of Gamezebo believed it would appeal to "word nerds and strategy-oriented thinkers". Pocket Gamer's Harry Slater commended the suspense inherent in waiting for an opponent's move, labeling Letterpress as "asynchronous gaming at its finest". Matthew Panzarino of The Next Web and Federico Viticci of MacStories both viewed the game as a worthwhile way to pass the time. However, some criticized its lack of a single-player mode.

Certain critics expressed concerns regarding the game's reliance on Game Center. Luke Larsen of Paste magazine lauded Letterpress as an "incredible achievement", but criticized its dependency on Game Center, which he felt impacted statistics tracking and matchmaking management. Dave Wiskus of iMore attributed Letterpress's absence of in-game chat and a rematch button to Game Center integration. Despite Wiskus noticing the lack of user interaction, he mitigated it with iMessage. He also highlighted problems while starting rematches, stating that simultaneous matches between players would be created. Viticci felt Game Center efficiently handled matchmaking in Letterpress.

Critics unanimously praised Letterpress's design. Ellis Hamburger of The Verge, noting the game's 6,346 lines of code, described the interface as "barren" with "natural-feeling animations". Nelson called the graphics "aesthetically pleasing", while Dellinger and Shane Richmond of The Daily Telegraph appreciated its clutter-free design. Nelson enjoyed the game's minimalist style and "smooth animations", drawing parallels to the productivity app Clear. Viticci noted similarities between Letterpress's visuals and Microsoft's Metro design language. Larsen complimented Brichter for the game's visually appealing menus and "smart aesthetic choices", echoing Wiskus's sentiment that Brichter "put a lot of love and care" into Letterpress. Friedman and Panzarino praised Letterpress's attention to detail, including its sound effects and user interface. Panzarino further praised the polished graphics and "reactive" animations. Ranking the game as a "must have", Chris Reed of Slide to Play deemed Letterpress a "gorgeous example of minimalist design". Brandon Sheffield of Game Developer used the game as a case study for design, noting its details, interactivity, and simplicity. Letterpress was among a list of minimalist apps provided to inspire Jony Ive, the lead designer for Apple's iOS 7.

• Official website
• Letterpress at MobyGames