Technology The app utilises a custom protocol,
BlueTrace, which allows for a distributed approach whereby participating devices exchange proximity information whenever an app detects another device with the TraceTogether app installed. The protocol, and reference app implementations of it, were also
open sourced as
BlueTrace and
OpenTrace respectively. Initial versions of the app required users to register using only their mobile number, since 7 April 2020, it requires users'
NRIC or passport numbers, and added support for
SafeEntry. The website states that the NRIC number was required in order to allow MOH to reach the right person when they need to give important health advice on COVID-19, and was stored in a secure server, never accessed unless needed for contact tracing, and never shared with other app users. The main goal of SafeEntry helps COVID-19 cases remember the places that they've visited. This helps MOH to identify potential infection clusters and perform cluster COVID-19 testing. Following installation, the user is requested to grant relevant permissions such as
Bluetooth. Android users are additionally required to grant Location permission as Bluetooth can be used to derive location information when combined with beacons in fixed locations. To trace users the
Ministry of Health (MOH) issues time sensitive anonymous temporary IDs that are used to identify the patient to all third parties. When two users of the app pass by, it uses the Bluetooth Relative Signal Strength Indicator (RSSI) readings between devices across time to approximate the proximity and duration of an encounter between two users. This proximity and duration information is stored on one's phone for 25 days on a rolling basis. The usage of the app had been limited by the technical limitations of needing to have the application to run in the foreground on iOS devices, and battery drain, but these problems had been reportedly addressed in the 2.1 version of the app released on 3 July 2020, and version 2.1.3 of 5 Aug added informational, work pass and SafeEntry QR features.
Release timeline The app was released on 20 March 2020, following 8 weeks of development by Singapore's
Government Technology Agency in collaboration with
Ministry of Health (MOH). On 10 April 2020, following the lifting of the embargo on the
Google-Apple Exposure Notification (GAEN) system, the developers announced that they had been working with Apple and Google on specifications which would allow for cross-border inter-operability, and had begun to incorporate these new APIs into TraceTogether. The developers envisaged this as a way to overcome the app's inability to access full background Bluetooth scanning functionality on iOS devices (which led to the app being active only when it ran in the foreground), and increase the pool of interoperable devices, both of which could have increased the contact tracing utility. He subsequently explained that the Government had decided against using the
Google-Apple Exposure Notification (GAEN) system, citing its inability to "identify how, when and whom the person was infected by or passed the infection to" and "the 'graph' not being available to the contact tracers". Instead, a new portable, wearable device, called the TraceTogether Token would be issued to all 5.7 million residents in order to increase the pool of participants. On 7 December 2020, market research firm
Gartner crowned TraceTogether as the Asia-Pacific winner for its 2020 Government Eye on Innovation award, after the firm had conducted a poll among various government organisations around the world. With the discontinuation of the system, the app has been removed from all official mobile app stores.
Uptake During the release of the app,
Minister for National Development Lawrence Wong, a co-chair of the multi-ministry Covid task force, explained that for TraceTogether to be effective, at least three-quarters – if not everyone – of the population had to install it, and had to turn on their Bluetooth function to ensure the app was running. This percentage increased to 17% of the population in May 2020. On 5 June 2020, the Minister-in-charge of the Smart Nation Initiative announced in Parliament that the TraceTogether has been downloaded on a voluntary basis by 1.5 million users, which worked out to only 25 per cent of the population. As of 14 December 2020, following the release of the token, adoption rate of the app and token combined exceeded 60% of Singapore's resident population. Despite falling short of the 70% adoption target that the Government had set loosen restrictions, On 23 December 2020, Balakrishnan revealed that the adoption rate had exceeded 70%. On 11 May 2021, Balakrishnan revealed that the adoption rate had exceeded 92%, with 4,923,054 individuals aged above six. There were about 3,000 users, or 0.056% of the registered users, who deregistered for reasons such as expats leaving the country, people who have died, or people opting out over
data security reasons. the contact tracing teams has improved their efficiency by reducing the time taken to identify and quarantine a close contact from four days to less than two days. the percentage may be low due to Singapore mandating mask-wearing since 14 April 2020. It was reported on 22 April 2021 that TraceTogether system had identified at least 75 persons who had to be placed under quarantine, but would likely not have been picked up through a manual contact tracing process. == TraceTogether Token ==