What is Underpass?
Underpass is a chat and file transfer app that features end-to-end encryption for complete privacy and security.
Communicate with another person or between your own devices.
Read the story of why I wrote Underpass and why you should use it.
What are the system requirements?
Underpass for iPhone, iPad, and iPod requires iOS 10.
Underpass for Mac requires Mac OS X 10.11 El Capitan or macOS 10.12 Sierra.
How do I get support?
For documentation and contact information, see Underpass Support.
Who is the developer?
Underpass was created by Jeff Johnson, an independent developer with over a decade of software engineering experience on Apple platforms. Jeff was a longtime engineer at Rogue Amoeba Software, working on apps such as Airfoil. Before that he was the lead engineer of Knox (originally developed by MK&C, later sold to AgileBits). Jeff was also previously the lead engineer for the open source RSS reader Vienna.