It could be an argument with a friend over what was said, an uncomfortable interaction with a co-worker or a routine police stop that turns sour. These are the kinds of situations that leave people wishing they could hit rewind on their lives and re-watch the situation to prove they were in the right.

A new smartphone app could be that reliable witness. Alibi works in the background to record audio, video and location 24 hours a day, seven days a week, to document what really happened when there are conflicting accounts.

"So many of us — you know, even myself — are constantly in situations where we wish we had been recording and didn't have the wherewithal to pull out our phone or ... a recording device at the time," said the app's co-founder, Ryan Saleh, in an upcoming interview with Nora Young on CBC Radio's Spark.

"The point of Alibi is to kind of make that a thing of the past, so that you're always recording."

​'A DVR for your life'

Saleh recalls a time police officers pulled him over in New York City while he was talking on his cellphone and driving. The first officer asked for Saleh's licence and registration, while the second officer asked him to roll down his window. Saleh complied, and the officer peered into his vehicle with a flashlight.

Two weeks later, Saleh learned from a relative who is a civil rights attorney that the officers acted beyond the scope of their authority. If Saleh had some record of the situation, the relative informed him, he could have filed a complaint.

His creation, Alibi, could have provided that proof. It's "a DVR for your life," he said.

Users download the app onto their smartphones. They only have to start it up once and Alibi will continuously work in the background to record audio, video and location.

After the app records for one hour all of the data is automatically deleted. None of the recordings are stored by the company.

If someone finds themselves in a situation where they want the data saved after an encounter, users can open the app and hit save. Alibi will save the last hour of recordings and hide the file on the person's phone so it can not be tampered with by anyone else.

"I use it at work. I use it in business meetings. Things like that," Saleh said. "It's proved useful on a couple of occasions."

At first, he was a bit worried about how he was acting and what he was saying when he knew Alibi was constantly recording his interactions. But, within a week, he warmed to the idea and his concerns eased. Now, he doesn't think twice about the app's surveillance.

Saleh believes people have changed how they view privacy, which makes them more comfortable using these kinds of technologies.

"I would say there's no question that our perception of privacy has changed over the past 20, 30, 40 years," he said.

Protests, police interactions

When Saleh created the app last year, he had various altercations in mind that it could be useful for: traffic accidents, harassment, bullying, spats between friends.Throughout the app's development, the news continued to highlight police killings of black men like Eric Garner; mass protests in Ukraine, Hong Kong and the Middle East; and the case of Adnan Syed, which was popularized by the podcast Serial.

Since it launched, Saleh said a lot of users have told him they find the app helpful during protests and police interactions.

He believes the app's surreptitious recording prevents people from escalating a situation, which they might do if they whip out a smartphone to openly record a police interaction.

Privacy concerns

In the U.S., people are generally free to record a conversation in public without letting other people know, Saleh said, so long as they are a part of the conversation.

It's a similar situation in Canada, said Steven Penney, a University of Alberta law professor. If someone secretly records a conversation they're involved in, Penny said, they won't run afoul of the law.

The same rules apply when someone wants to record the police, he said.

"In many sensitive or difficult situations, the police might not wish to be recorded," said Penney. "But they really don't have a right not to permit people to record them when they're operating in public spaces."