The Catholic liturgical calendar. Every day of every year, with notes on saints.
You get a free one-month preview of the Universalis pages, which contain the Readings at Mass (with a choice between the Jerusalem Bible/Grail and the NAB translations), the Mass Today (which combines the daily Mass readings with the Order of Mass) and the Liturgy of the Hours: Morning Prayer, the three daytime hours, Evening Prayer, Night Prayer, and the Office of Readings.
If you like what you see in the one-month preview, you can take out a monthly subscription to it or you can buy the Universalis app instead.
You can purchase or subscribe to audio for all the Hours (spoken in English), the Gospel of the day (Jerusalem Bible, spoken in English), or the daytime Hours (Terce, Sext, None) spoken in Latin.
This app is complete in itself. It needs no Internet connection and no downloads.