Liber Pro takes the 1961 Liber Usualis, a book of over 2,300 pages of Gregorian Chant for use throughout the liturgical year, and literally puts it at your fingertips on your iPhone or iPod Touch. Liber Pro adds to this tome a linked table of contents, user-defined bookmarks, vertical and horizontal paging and zooming, browser-like navigation, a dynamic liturgical calendar, and more.

Liber Pro is more than just an eBook. It is also a complete 1961 Roman Calendar, capable of calculating the moveable feasts throughout the year automatically. This means you can select a date; view the proper, common, and feria for that date; and jump instantly to the relevant pages in the Liber Usualis.

- 1961 Liber Usualis: over 2,300 pages
- Scroll, zoom, and page with touch gestures
- Simple “Back” and “Forward” buttons traverse browsing history
- Browse in portrait or landscape orientation
- Auto-centering keeps content in view when paging
- Option to hide view selector for additional viewing area
- Selectable paging direction: up and down or left and right
- Selectable overlay eases page viewing

- Calculates the day’s feast from the calendar of 1961
- Links to the starting page of the proper, common, and feria of the day
- Select today, the next or previous day, the next or previous week, or choose a day with a date picker

- User-defined bookmarks retain page, position, and zoom
- List of bookmarks can be reordered and individual bookmarks deleted

Table of Contents:
- Extensive table of contents provides links to Masses, offices, rubrics, and much more

- Provides links to the 100 most recently visited pages this session

What’s New

Version 2.1

- Update for iOS 11
- Calendar fix for the Vigil of Christmas falling on Sunday
- Fixed zooming issues from previous version
- Support for split screen on compatible devices
- User-selectable control over the following paging behaviors:
- Center page after swipe (on by default but can now be turned off via Settings app)
- Bounce off edges when scrolling (on by default but can now be turned off via Settings app)
- Page margin

Ratings and Reviews

4.8 out of 5
4 Ratings

4 Ratings

guardajoias ,

An excellent update to a brilliant application

This update brings Liber Pro to full compatibility with iOS 8 and 9, and the larger iPhone screens. Thank you. There are also several welcome adjustments. On an iPhone 6 with iOS 8, the screen is now well used and makes it much more efficient for liturgical use. The zoom is indeed a bit quirky, but this is much less required than before on newer screens, as in landscape mode, the page is perfectly readable and accessible. Hopefully that can be fixed in a subsequent update. The combination of a reliable calendar with all the pages of the Liber Usualis is just brilliant.

IrethCalmcacil ,

Fantastic on the iPad Mini

I recently got an iPad Mini 4, and almost the first thing I did after opening it up was purchase Liber Pro. I sing in a Gregorian Chant schola at my parish, and this app is fantastic. The calendar brings me right to the propers I need to sing for any given day, and I love that I can add bookmarks to quickly take me to different mass settings/propers/etc. No more lugging around a book, and no more noisy flip-flap-flip-flap of pages frantically turning back and forth to find the pages I need to sing. Thank you, Drake Applications!

C4_993_Driver ,

Very appreciative of the effort, but...

Such great potential, but this falls short in terms of practical use. Yes, it's not an eBook as another review mentioned, but the pages don't have an adjustment where a single page cab be viewed. I chant in a schola, and not being able to see a complete page is rather limiting. In addition, the page "turning" is very slow to resolve. The next page "snaps" in place and ruins the flow. Think of this as the chant moves from one page to the next. Virtually unusable.

In addition, although there are bookmarks, the app is very slow. One has to access the "bookmark menu", press the desired bookmark, and then let the app think about it. By the time the screen finally resolves, the flow of following is ruined -- especially for the short variable parts such as the Introit.

This has great potential, but the slowness of the app and the lack of customization doesn't leave me with a positive experience. This would be a tough app to recommend.


Drake Applications
125.1 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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