The HSE feared losing public confidence over a flaw in the Covid-19 tracking app that was draining the batteries of some mobile phones.
Internal emails reveal how 12,000 people had deleted the app within a matter of hours of the problem first being reported.
At one stage, the loss of users was down by more than 83,000, according to records released in response to a Freedom of Information request.
The development team working on a fix were told it was needed “ASAP” and that time sensitivity on solving the problem was key.
One email said: “We’re back into a work week tomorrow and people will not be able to survive without a phone; the risk is that we lose public confidence and start seeing high rates of deletion.”
Developers were also worried that fixing the issue might create new problems but were “sprinting” to push out an update for the app.
An email sent from Google to the HSE said: “This issue is our highest priority – we’ve been sprinting on a fix that we can push out as fast as possible without creating risk of inadvertently making things worse.”