I love the convenience of taking my iPhone and iPad to church with so much information, especially since I have young kids. I have all my manuals, study guides, scriptures, calendars and notes in one easy place. The LDS Church apps LDS Tool is very helpful too, considering your ward/stake directory are all in one place.
The one thing that really bothered me about the Gospel Library app was it’s lack of music — it only had the words — no notes or time signatures. So I usually brought along my mini hymn book or opened a real one so I could better contribute and follow along. But the Church released a new app called LDS Music (find it here) that includes all of the information in the hymn book! You’ll love it. It’s even available for iPad. Check it out here and install it for Church tomorrow. I promise you’ll love it!