The UK's counterpart app was also delayed this evening.
Dr Tony Holohan said there is no date available for when the Republic of Ireland will be in a position to roll out its contact-tracing app, and no guarantee it will be on an all-island basis.
Speaking at this evening's Covid-19 briefing at the Department of Health, Dr Holohan said that "good work has been done", but no firm date is available for when the app would become part of Ireland's response to Covid-19.
Paul Connors, National Director of Communications at the HSE, said at a briefing on March 29 that the app was a “very important piece of technology” and that it was "likely" to be introduced "in the next 10 days or so".
The UK government this evening also were unable to give a date for the roll-out of their version of the app, with Health secretary Matt Hancock announcing that due to issues found while testing the app on the Isle of Wight, they would be moving to a Google/Apple version of the app.
Speaking this evening, Dr Holohan said that the Irish app was discussed at NPHET today, but he couldn't "give a precise date when it's going to be ready for commencement, but good progress has been made on it."
Dr Holohan was keen to stress the importance and effectiveness of the current contact tracing system in place already, saying the app, when rolled out, would be "a very important adjunct to the contact tracing activity that happens through the public health teams".
He said it could be used "to give access to information that perhaps might not be identified by a person, who may not know they had important contact".
When asked about whether the app would be used on an all-island basis, incorporating Northern Irish residents, Dr Holohan said it was "under consideration", but he could not give a definitive answer whether it would be used in all 32 counties.
Dr Holohan said that "everywhere we can identify areas that we can cooperate on, we do, and this may well be one of them.
"We've given advice to government already in relation to the whole question of the island and the border and the role in relation to travel.
"Anything that we think can help in the management of the disease from that point of view will be of value to us. So if the app can help us in that regard, then that would be welcome", he concluded.
