Two monthly devotions with conditions attached.
First Fridays: receive Communion on the first Friday of nine consecutive months, in honor of the Sacred Heart.
First Saturdays: on the first Saturday of five consecutive months, go to confession, receive Communion, pray five decades of the Rosary, and keep fifteen minutes of meditation on the mysteries, in reparation.
Confession within about a week either side counts for both.
Both devotions attach a promise to a habit, and the habit is the real gift: nine or five months of regular confession and Communion changes a person whatever they make of the promise.
The First Friday devotion comes from the revelations to Saint Margaret Mary Alacoque at Paray le Monial in the seventeenth century.
The First Saturday devotion comes from Fatima, and the Church approved those apparitions as worthy of belief in 1930.
Entirely free, and rooted in private revelation, which no Catholic is required to believe even when the Church approves it. Treating the promise as a guarantee that makes repentance unnecessary would empty it.