TORONTO -- Canada has become the latest country to announce it would begin using a contact tracing smartphone application to help mitigate the spread of COVID-19.

Prime Minister Justin Trudeau told reporters Thursday that the 鈥渃ompletely voluntary鈥 app will be available in early July to any Canadian that wants it. It uses Bluetooth connectivity to track when two devices come in close contact with each other and if a user tests positive for the virus, the app will notify anyone that had come in close contact with that person鈥檚 phone.

While contact tracing apps have been rolled out elsewhere,not every country鈥檚 app has had a smooth roll out.

Here are four takeaways from other countries that have developed contact tracing applications:

PRIVACY CONCERNS ABOUND

The big concern with these apps internationally is privacy. examined 11 contact tracing apps from Europe, north Africa and Asia, and found some of the apps are 鈥減utting the privacy and security of hundreds of thousands of people at risk.鈥

The organization found Bahrain鈥檚 鈥淏eAware Bahrain,鈥 Kuwait鈥檚 鈥淪hlonik鈥 and Norway鈥檚 鈥淪mittestopp鈥 apps to be particularly troubling for the users鈥 privacy, as they use GPS data and allow for real-time tracking of its users. Norway has since paused the use of its app.

鈥淭he Norwegian app was highly invasive and the decision to go back to the drawing board is the right one,鈥 Claudio Guarnieri, head of Amnesty International鈥檚 Security Lab, said in a news release. 鈥淲e urge the Bahraini and Kuwaiti governments to also immediately halt the use of such intrusive apps in their current form.鈥

Trudeau said Thursday that the privacy of Canadians 鈥渨ill be fully respected,鈥 and that location services would not be used for the app, meaning it would not use real-time movement tracking.

Amnesty International added that apps using a decentralized model of Bluetooth contact tracing, such as Canada鈥檚, 鈥渢end to be less concerning from a privacy perspective.鈥

MADE POSSIBLE BY GOOGLE AND APPLE

Similar to Canada鈥檚 app, Google and Apple are involved in several of the contact tracing applications around the world.

In May, both companies released a software tool that allows developers to use the Bluetooth capability of smartphones to detect each other, while also maintaining the user鈥檚 privacy.

Switzerland, Germany and Italy have already launched apps based on this model. Last month, Apple and Google said that health agencies from 22 countries and U.S. states are using the tool to develop their own app.

Canada鈥檚 app, while developed by Shopify, Blackberry and the Government of Canada, is also using this tool from Google and Apple.

Applications using this software tool could help in the long term with international travel, as each country鈥檚 app could in theory communicate with each other.

QUESTIONS ABOUT EFFECTIVENESS

While many countries are just now rolling out their apps, some countries that have had them since earlyspring now say they weren鈥檛 exactly the game changer that they had hoped.

In Iceland, developers launched 鈥淩akning C-19鈥 in early April and it was quickly downloaded by 38 per cent of the population, but its impact has been minimal.

鈥淭he technology is more or less 鈥 I wouldn鈥檛 say useless,鈥 Gestur Pálmason, a detective with the Icelandic Police Service overseeing contact tracing efforts, 鈥淚 would say [Rakning-19] has proven useful in a few cases, but it wasn鈥檛 a game changer for us.鈥

A study out of the inApril, shows that contact tracing apps can help stop an epidemic, but only if approximately 60 per cent of the population uses it.

In Singapore, 鈥淭raceTogether鈥 launched in April, but its lead developer was quick to temper expectations surrounding the product.

Jason May said the app would not be a 鈥減anacea鈥 for the spread of the virus and that it is only meant to complement the existing tracing efforts.

鈥淵ou cannot 鈥榖ig data鈥 your way out of a 鈥榥o data鈥 situation. Period,鈥 May wrote in the post.

NOT A PRIORITY FOR SOME COUNTRIES

In the United Kingdom, a contact tracing app had been a focal point of its response to the virus, with an initial plan to release their app in mid-May, but now the British government has said it won鈥檛 be ready before winter.

The U.K. government had intended to develop an application without the help of Apple and Google鈥檚 software tool, but have now change their minds. The government added that the delays are simply because it is no longer a priority, as they鈥檝e noticed that people would rather hear any potential bad news from a human voice, rather than a notification on their phone.

鈥淥ne of the things it has taught us is that it is the human contact that is the one most valued by people,鈥 James Bethell, the minister for innovation at the Department of Health and Social Care, told the U.K.鈥檚 Science and Technology Committee on Wednesday.

鈥淚n fact, there is a danger of being too technological and relying too much on text and emails and alienating or freaking out people because you鈥檙e telling them quite alarming news through quite casual communications.鈥

In the United States, indicates that more than 71 per cent of Americans would not download a contact tracing app if it were an option.

With files from 麻豆影视 Ottawa News Bureau Online Producer Rachel Aiello