Signal is getting a strong signal of its popularity.
The encrypted messaging app, made by Open Whisper Systems, has seen a 400 percent increase in installations since last week's presidential election, co-founder Moxie Marlinspike told American Public Radio's Marketplace program.
Marlinspike didn't specify how many users the messaging app had, but said "millions of people" used it before the November 8 election of Republican Donald Trump.
"We've never really seen any single event in the past that's resulted in this kind of sustained, day-over-day, interest," Marlinspike said.
Signal uses end-to-end encryption that scrambles a message so that no one other than the sender and recipient can read it.