New figures show almost 90,000 people have deleted the HSE's COVID Tracker app since it was launched.
It comes as an update is being rolled out by Google to fix the app, after Android users reported that it drained their phone batteries.
The Health Service Executive says it was notified on Saturday by some people with Android phones that their batteries were running down quicker than usual.
A fix has been pushed out by Google, which is set to resolve the problem on affected phones.
The HSE, NearForm - which built the app - and Google have also implemented additional measures to improve the resilience of the exposure notifications system - and to ensure that these types of issues do not happen again.
The HSE has apologised to anyone who experienced any problems over the weekend.
A mobile phone showing the COVID Tracker app. Picture by: Leah Farrell/Rollingnews.ieIt says 1.56 million people have completed registration since the app was launched, with approximately 780,000 of these on Android phones.
But it says that 86,000 Android users have uninstalled and not re-installed the app.
Newstalk's technology correspondent Jess Kelly explains.
"It transpired that it was an issue with the COVID Tracker app."
"It seems that an update that occurred from the Google Play Services side saw an impact on the exposure notifications.
"So you know if you have the app on your phone and you might see this little sun logo up in the top left-hand side - that'll pop up every now and then, that is the exposure notifications.
"That is when my phone and your phone does that 'bluetooth handshake' to say we're within sort of touching distance, or we're closer than we should be.
"That seemed to act up for some reason over the weekend and it caused a massive issue".
Google says this was something that was only specific to the Irish COVID Tracker app.
