FiftyThree, Inc. was an American privately held technology company that specialized in tools for mobile creation and creativity.

[1] They were the makers of Paper, Apple's 2012 iPad App of the Year,[2] Pencil, a digital stylus, and Paste, a collaborative presentation tool.

[6] Initially operating out of Petschnigg's apartment, they began work on their first product, Paper, which launched in March 2012 and was chosen by Apple as the iPad App of the Year.

According to a 2013 article on Wired, the name FiftyThree references the physical space in which a person creates: "An average human's arm's reach is 53 centimeters ... a sort of invisible sphere encompassing head, heart, and blank canvas.

[9] The team is composed of employees who have previously worked at Microsoft, Sonos, Google, Adobe, Apple, and Nike, among other companies.

[10] In June 2013, FiftyThree announced raising a $15 million Series A round of funding, led by Chris Dixon at Andreessen Horowitz.

Other investors included SV Angel's Ron Conway, Highline Ventures' Shana Fisher, Thrive Capital's Josh Kushner, and Twitter / Square founder Jack Dorsey.

[13] They have subsequently partnered with (RED)[14] to raise awareness and funds for AIDS, GE[15] to use art to visualize brain activity, and Skillshare[16] to teach classes using Paper.

In March 2015, FiftyThree announced raising a $30 million Series B round of funding, led by Dayna Grayson at New Enterprise Associates (NEA).

[20] Paper contains digital journals in which users can create sketches, diagrams, illustrations, notes, or drawings, and share them by email or across the web.

The addition of Presentation Mode followed shortly, which allows users to hide the tool tray and menus when Paper is connected to a second display or projector.

[27] Mix contains templates, outlines, tutorials, notes, and sketches, and all creations shared are committed to the Creative Commons Universal Public Domain.

The feature Global Search was also added, which enables users to find and follow people on Mix by their names and emails.

[31] In May 2015 FiftyThree announced Think Kit, three additional free tools in Paper geared toward creating charts and diagrams.

It detects and corrects dozens of shapes sketched in real-time, enabling users to create presentation-ready charts, diagrams, graphs, flows, wireframes, and models.

[40] In November 2014 Mobile Mouse and Autodesk's Sketchbook were added to the list of Pencil-ready apps,[41] followed by Microsoft OneNote, Adobe Illustrator Draw, Adobe Photoshop Sketch, PicsArt Photo Studio, Tayasui Sketches, Astropad, PDFpen 2, Flowpaper, and ZoomNotes in 2015.

Surface Pressure changes the variance of the lines drawn in Paper based on responsive transitions between Pencil's broad edge and tip.