In late March 2020, Singapore was one of the first jurisdictions to implement an, ENACT app. Singapore’s TraceTogether app uses Bluetooth signal strength to detect proximity to other users. TraceTogether’s source code was published for the world to use as a template for other ENACT apps – the open source template is called OpenTrace. Unlike the GAEN design, OpenTrace relies on a centralized body to do the actual contact tracing. While some jurisdictions, like Australia and Alberta, have used OpenTrace to build their app, the GAEN API seems to have the popular vote. ENACT apps inherently exclude certain individuals from participating in digital contact tracing. These apps will only work on newer versions of Apple and Android products, users need an internet connection once a day to get accurate results, and users need to be able to properly use a smartphone. These requirements exclude families who cannot afford the latest phones, people who do not have reliable internet access, non-technologically capable people, and others. As a potential solution, Singapore has recently released “contact tracing tokens” which perform the same task as their local ENACT App, but do not require a smartphone to use.