Step outside and look up. What do you see? Maybe some clouds and the blink of a passing aircraft. Perhaps the smudge of a star or two against the haze of a nearby city’s light pollution.

Open Night Sky, point your device up and you’ll see the universe open its doors; all of the stars and constellations overlaid on the abyss with guides to the stars and planets above. Move your device, and your window to the sky moves with you.

This beautiful invitation into space might be one of the most insightful apps ever made, yet it was created by a secondary school music teacher with just a passing interest in astronomy.

“At the time it wasn’t about me developing it as a career. It was all so fresh and new back then that you didn’t know where it was going to go... It was just a hobby.”

Weekes started developing apps. A lot of them.

“I made 33 apps before Night Sky,” he explains. “They weren’t great. I was using open source code to play around and develop very simple ideas, initially. Many of them were basic soundboards. With each one, I learned something that led me to trying different things.”

“Eventually I came across a piece of code that was used for mapping the stars. I used the open source base code and adjusted it, adding things like the ability for red vision – which makes everything on the screen turn red so the users’ eyes adjust to it. I released it under the name Night Sky.”

Following a tepid response to his first efforts, Weekes couldn’t have anticipated the instant hit Night Sky became.

“It was released on November 1st, 2011 and it instantly took off,” he explains. “It got to the stage where I was checking the charts every couple of hours because it was just going up and up. By January 2012 it was the number one app in the UK charts. It was just unbelievable.”

Months later Weekes was a full-time developer, taking his new passion for space and partnering with coders and astrophysicists to push Night Sky to the next level.

In the subsequent years the app has remained an ongoing favourite with App Store users around the world, largely due to constant improvements.

You can now explore the solar system in AR, dropping stars, constellations and planets into your living room. You can track passing comets, satellites and even the International Space Station. You can go on guided tours of the sky above your home on Apple TV, or see the current stargazing conditions on your Apple Watch.

“We try to take advantage of the new technologies,” Weekes explains. “That’s pushed the development of the app over the years. We’ve also got a very engaged user base who regularly email me saying, ‘Could we have this?’ or ‘Could you do that?’.”

“We take a lot of the feedback on and it’s helped develop the app over time.”

It’s not just new feature ideas that users have shared with Weekes. He often hears of amazing ways in which people are using the app.

“There are websites where people can buy a star in memory of somebody,” he explains. “We regularly hear from users that they’ve actually managed to locate these stars using the app. That’s really nice to hear.”

“There was also a tweet from astronaut Cady Coleman who said how great the app was. That’s a US astronaut who has actually been in space.”

For Weekes, however, it’s his educational roots that remain at the core of the app.

“To have gone from being a teacher in a single school to creating an app that is educating millions of people on a daily basis, that is phenomenal,” he says.

“It’s hard to get my head around how big this has become. I can lie there at night and think that at that exact moment people all around the world are using the app. It’s just mind blowing.”