PuppyDo

PuppyDo uses the build in Reminders app as its database. Which means it will use the reminders that you have created and display them as ToDo's in PuppyDo.
New todo's that you create in PuppyDo will also be created as reminders for the Reminders app.
This is also true for editing and deleting.

In short there is no big difference between a reminder and a todo taks.
The main difference is the way PuppyDo displays the data. It only shows one task at the time, when you want to see everything you have to go through them one by one.
This may seem cumbersome, but it can also help you recall the todo taks better in your memory.
To make the display of the todo more rememberable and enjoyable each todo is coupled with a random picture of a puppy. Which can motivate you to scroll through the todo list multiple time.

Additionally there is an option to use custom photos instead of the pre selected random pictures provided.