You know you should be grateful for everyday. Why not use your favorite blog platform to help you in this.
First off, I would like to say these are the places that helped in getting this plugin going, and the how to do this stuff:
A lot of the code love learning came from: http://www.yaconiello.com/blog/how-to-write-wordpress-plugin/ Displaying the template, if it doesn't exist: http://wp.tutsplus.com/tutorials/plugins/a-guide-to-wordpress-custom-post-types-creation-display-and-meta-boxes/
Some of the advanced options stuff came from reading the source code of the pulse press theme and the Coraline theme.
Now, some of the other information, that you would like to know. It is said that the best way to lead a very full life, full of the good stuff is to be grateful. How do you go about doing that, a lot isn't written about it, and usually takes either just paper journaling or what not. But what if you had the template ready to go, and using your own favorite theme. This is where my plugin comes into play.
By using this, you get a proven plugin template for doing a daily gratitude journal, with the right blanks to fill in. You just supply what you are grateful, using a theme that goes great with your personality. If you don't like how my template looks, it is just a custom post type, so it can be extended in your theme to include it, along with how you want it to look.