Are you in the middle of D180 and looking for a specific link?
Liturgy of the Hours
Along with the Mass, the Liturgy of the Hours is the official prayer of the Church. D180 recommends that you  pray Night Prayer, and you may be interested in praying other hours as well. The Hallow app has
Lectio Divina
Prayerfully reading scripture is a cornerstone of the Christian life. The Hallow app has an excellent guide to Lectio Divine, including a clear explanation and step-by step instructions.
Struggling With Chastity?
If you find yourself struggling with chastity, know that you’re not alone. His Mercy Endures offers straightforward advice and practical resources for dealing with temptations to pornography and unchaste dating. Take the time to be intentional about growing in the virtue of chastity.
To Save a Thousand Souls
An important part of D180 is reading To Save a Thousand Souls by Fr. Brett Brannen. It explains what priests do, what qualities are necessary to become a priest, and how to discern whether you are called. To finish the book within 180 days, it is necessary to read two pages per day


If you have finished To Save a Thousand Souls, there are many other books that are particularly helpful during a period of intentional discernment. Here are just a few:

Virginity, Raniero Cantalamessa; a guide to celibacy for the sake of the Kingdom as it truly is: a gift to be received, not a burden to be imposed.

Discernment of Spirits, Timothy Gallagher; a guide to understanding the different movements of spiritual life, how to recognize which are from God, which are from the enemy, and how to respond to each.

The Priest is Not His Own, Fulton Sheen; a reflection on the priesthood of Jesus Christ, who offered the sacrifice not of a separate victim, but of Himself.