SINGAPORE - Late last year, the ubiquitous TraceTogether app saw an addition that brought a smile to many people's faces.

Upon checking in at a location, a smiling otter pops up, swimming leisurely across a teal-coloured check-in pass on the screen.

The moving animal brought much-needed levity to what some have found to be a grim process. One user has touted it the "kawaiification of TraceTogether", a reference to kawaii, or the culture of cuteness in Japan.

Behind the page's success is Government Technology Agency (GovTech) designer Joycelyn Chua, 30, who told The Straits Times last week that she initially intended the animal to dance across the page.

"The designer whom I was illustrating the animation to said that it was a bit difficult (to make it dance)," she said. "She then suggested we have it move horizontally with its legs kicking like it's swimming.

"I was like, 'You are right, otters swim, they don't dance.'"

Ms Chua is one of the leaders of the TraceTogether team, comprising about 20 people. They developed the new check-in page and had it up and running on the app within three weeks of the Ministry of Health easing dine-in restrictions last November.

She has been with GovTech for five years, and previously worked for the Ministry of Manpower, after studying psychology and supply chain management in school.

The otter is her idea, beating out the Merlion because it has the letters "tt" in its name, which TraceTogether is often shortened to.

With restaurants needing to quickly check patrons' vaccination status, the team decided that the app needed a new feature. People were flashing their vaccination certificate to restaurant staff before toggling to the check-in page, a small inconvenience that was multiplied manifold with millions of people using the app.

"We know that people were fumbling so we wanted to combine it to show it on just one screen. The vaccination certificate was also quite small so staff had to peer in. We decided that our solution had to be something that could be sighted from afar," she said.

For those who are unvaccinated, the page will be in white, instead of teal. Asked why it was not red - a more common colour for access denied - Ms Chua said the team did not want those who are unvaccinated to feel discriminated against.

"There were colour-blindness considerations but the key reason is because we don't want to discriminate. They have their own personal reasons for not taking the vaccine," she explained.

As has been much speculated, the moving otter was also to prevent people from using screenshots of vaccine certificates to check in to places.

"We didn't know if people would be willing to accept the change, but we did some testing with the people around us and they liked it," said Ms Chua.

TraceTogether faced some backlash when it was first introduced, with many people worried that the digital contact tracing tool could track their location.

Ms Chua said she recognised very early on that to get as many people on board as possible, TraceTogether would have to be more than functional.

It had to "gain the trust of the people", she said, and one way to do it was to bring warmth and little joys to them when Covid-19 measures were weighing them down.

"The otter was one of my attempts at doing so. When people first downloaded the app, they were also greeted with a letter titled 'To the people of Singapore, with love'," she said.

"There were several people, including my bosses, who asked me why not use 'To Singaporeans, with love', since that's much catchier. I agreed, but felt we have non-Singaporeans among us who are equally important."