You decide how often (up to 4 times a day) you want an e-mail which asks you what you're grateful for. When it arrives you can answer it whenever with whatever you want that you're grateful for.
I have it set on 1 a day in the evening. Lately I've been scooping them up several at the same time (lazy me) but it keeps me thinking of what I'm grateful for in my life. I can also go to the website and log in to see all my entries (and edit them if must). It really makes me think and remember all the things I'm happy to have in my life.
Some of my recent entries:
I'm grateful for all my books.
I'm grateful J said we should go into Marienkirche, so beautiful which makes me even more keen to see Notre Dame.
I'm grateful that the weather in August has become better.
I'm grateful for the existence of wikipedia.
What are you grateful for?