The gadget, which costs $109 (£85), can be worn as a bracelet and is activated by making the sign of a cross.
It is connected to the “Click to Pray eRosary” app, which is designed to help Catholic users pray for world peace and contemplate the gospel.
The app tracks a user’s progress, and contains visual and audio explanations of the rosary.
The traditional rosary is used to aid prayer and meditation. Its beads are counted as prayers are recited.
Users can choose from three ways of praying. There is the standard rosary, a contemplative rosary or a thematic rosary.
The rosaries are made up of 10 black agate and hematite beads, plus a metal cross that detects movement.
“This project brings together the best of the Church’s spiritual tradition and the latest advances of the technological world,” a Click to Pray press release said.
Taiwan-based tech company GadgTek Inc developed the gadget, which is water-resistant and compatible with Android and iOS smartphones.
This is not the first time the Catholic Church has attempted to attract young people with technology.
In 2018, a Catholic evangelical group launched “Follow JC Go!”, a Christian take on the hugely successful Pokemon Go gaming app.