Runeterra Bible is a companion app for the card game - Legends of Runeterra.
Right now it is a very simple app that I have been using during games to remind me of spell cards during certain matchups.
For example, in the pull-down menu in the spells section of the app, you could quickly select the regions Ionia and Shadow Isles then tap removal. This will show all the dangerous removal cards such as Black Spear, Atrocity, Vengeance.
I will be adding more features over the next few weeks though. Check out my companion app for Team Fight Tactics - TFT Bible, for a rough idea of things I will be adding.