The Daily Roll Call is a 90-day-long program that allows you to receive various Rewards, such as Units, Boosts, Resources, Diamonds, and other valuable Items for each day that you log into the game.
Rewards are sent to your Base instantly upon login. In order to check to see what you have received, tap on the Elite icon at the top of the screen. You will see your Reward in the Daily Roll Call tab. The Rewards you have already received are highlighted with a check mark on the left.
Diamonds, Resource Packs, and other Items received as part of your Daily Roll Call rewards are stored in the corresponding tabs of your Inventory.
Once you successfully reach Day 90, you will receive a large reward, and the cycle will restart from the beginning.