The Grimoire whilst detailed is totally wasted in my opinion by being locked off to a separate app (which I personally find has a convoluted and difficult to use interface). Most users wont bother or see it, and it loses context when viewed later, ie if I collect a special gun that has grimoire attached I want to learn about it immediately not a few hours later by which time the moment has passed and i will no longer care. With the game being social and you playing with friends, you cannot be randomly stopping to pick up your phone to read the grimoire, or even if it was integrated stopping to READ would not be appropriate, hence why it should be integrated AND with an audio transcription, thus allowing the player to instantly hear relatable context driven lore without interruption to the gameplay or disruption to your fellow fireteam members. Bioshock infinite handled this in an excellent way, such as in the link above. They present it as collectable audio files, which when collected would not instantly play (allowing the player to continue without any interruption if so desired, ie they are midway through a tricky battle), however they could quickly tap a button (perhaps the options button or touch pad) to have it play the audio transcript of the grimoire. These could then be accessible from your inventory for later reading OR listening. which would allow cost effective introduction of new voice talent/characters to bring life to the world. Additionally this integrated approach would allow the introduction of of richer side quests or tasks to be accessed within the patrol sections. For instance, you pick up a grimoire which relates to the last hold out of a legendary hunter on the moon, this could then add a mission marker to the patrol section of the moon, which allows you to fight your way to X, to find where he fell, and retrieve his sniper rifle, and an additional grimoire which completes his audiojournal/narrated micro story.