With all the Rebate apps, it can get confusing. Here's what I do.
I have a "page" on my phone with all the grocery rebate apps in one place.
I keep a notebook of all purchases, coupons used, and rebates submitted. When I receive the rebate, I highlight it in the notebook. I can look back and make sure I received all my rebates and contact help on the app if needed.
Freezer Inventory
I keep a list of what I put in the freezer. It is organized by freezer storage life. I put a circle beside the item for each package I add. I write the date and amt in the circle. I mark the circle out when I take it out of the freezer. This way I am not digging through the freezer all the time to see what I have. I can look at the inventory and quickly see what I need to use soon and what I am low on.
Pantry Storage/Stockpile
This can get tough because I never have enough storage space! But here's the general idea. I lay boxes down on the shelf so that the expiration date shows, then stack like items together with the ones expiring the soonest on top.