A statement from the Catholic Church said the app aims "to help you go deep with God, and build solid ground with Him through prayer, through the lives of the Saints, and Scripture".
There are daily prayers and "questions to prompt reflection", such as "What is the Gospel saying?"
The app also has a diary so users can write down their answers and thoughts to these questions and track their "growth".
In mind of its target audience, it also has a link to the Twitter feed of the Pope and the latest Roman Catholic news, including a monthly quiz and a guide to new retreats or latest prayer festivals.
Listen up! Are you hearing God's call? We have just released a new vocations app, designed to help young adults grow in faith, develop in discipleship and follow God's call. Download your free 'God Calls' app from https://t.co/JVCzgBVGAh pic.twitter.com/lkjL4y2eEn— NOV (@ukvocation) January 4, 2018
The app was created by the National Office for Vocation of the Catholic Bishops' Conference for England and Wales.