Revenant

Revenant is a sealed letter to your future self. You write what is on your mind today, and you choose the numbers that matter to you — the price of fuel, groceries, rent — each one a real figure from an official source, kept with its date and where it came from.

You pick a date to open it. Then you seal the letter. Once sealed, it cannot be changed, not even by you, and no one else can read it.

When that date arrives, the letter opens. First it asks how you remember things. Then it shows what you wrote, and the numbers then beside the numbers now. The space between the two is yours to read.