Hailed as the 'perfect aid for every penitent', it promised absolution to a guilty conscience on the move.
But a confession app for religious iPhone or iPad owners has evoked the disapproval of the Vatican.
The snappily-titled Confession: A Roman Catholic App was thought to have been approved by the Catholic Church after a U.S. bishop granted it an imprimatur, the church's official endorsement.
But the Vatican has warned that an app can never replace visiting a priest.
Spokesman Federico Lombardi said: 'It is essential to understand that the rites of penance require a personal dialogue between penitents and their confessor.
'It cannot be replaced by a computer application'.
'I must stress to avoid all ambiguity, under no circumstance is it possible to "confess by iPhone".'
The app measures the user's age, sex, occupation and how much time has elapsed since their last confession.
Its 'examination of conscience' then decides what penance to impose -- it even comes with seven acts of contrition to choose from.
Developer Little iApps, a three-man team based in Indianapolis, describes the app as 'a step-by-step guide to the sacrament, inviting Catholics to prayerfully prepare for and participate in the Rite of Penance'.
An impressed Bishop Kevin Rhodes, of the Diocese of Fort Wayne -- South Bend, was said to have granted the app an imprimatur, an official endorsement from the Catholic Church.
Little iApps' Patrick Leinen said: 'Our bishop was very excited about it.
''We were able to work with several priests in order to get that examination of conscience created, so it was kind of fun.
'The imprimatur itself was pretty neat.' Mr Leinen knew he was on to a winner when he tried the app out on a man who hadn't been to confession in a long time.
He said: 'When we were actually testing out the software before release we had one gentleman who hadn't been to confession in about 20 years.
'He did his confession with it and he said it made it much easier on him.' The app is available to download from iTunes for £1.19 ($1.99).
© Daily Mail, London