Google, Apple Covid-19 contact tracing apps could fail

When Google and Apple joined hands to create a solution for contact tracing Covid-19 individuals using Bluetooth signals from their smartphones, little would they have imagined that previously ignored incompatibility issues could haunt them to such an extent.For, researchers are now claiming that despite the best efforts from the two tech giants, as many as two billion out of the 3.5 billion total smartphone users could be left out of this exercise.  All because, the two companies did not taken into account the multiple versions of Bluetooth that smartphones have carried over the years. 
Their scheme currently relies on specific wireless chips and software that could be missing from millions of smartphones that are in active use and were released five years ago. The problem gets compounded when realization dawns that such phones could be in the hands of the elderly and the poorer sections of society, easily the two most vulnerable segments to Covid-19 infections. Out of the estimated 3.5 billion smartphones used globally, at least 25% of them may not have Bluetooth low energy chips. It is also being estimated that 1.5 billion mobile users are using older ‘feature phones’ or other non-smartphones. All of these aspects are bound to make contact-tracing far less effective.
Compared to more than 80% compatible devices in the US and European countries, it is estimated that only 30-40% mobile users in India would have compatible handsets. The new app from Google and Apple should become available by mid-May.In India, the government is vigorously promoting it’s Aarogya Setu app for contact tracing. It is available for both Android and iOS devices. New reports suggest that the India government is planning to use the app as an e-pass to track the movement of people once the lockdown restrictions are eased. First, the data given by the user will be evaluated to ascertain if the user is healthy and not affected by Covid-19. If not, the app will show green colour indicating that the user is safe. Then, as the user moves around, the app can issue a warning when the user is near a high-risk area.
How effective is the Aarogya Setu app?