sChecklist is a simple, portable app that lets you create checklists so you can check, or uncheck tasks.

While there are other similar apps, like ToDoList, the author created this one to fill a niche he had. The niche was a straightforward checklist.

You can create numerous checklists, with multiple entries. Once a task is completed, you can uncheck it. That said, there are quite a few features and options:

Mulitple list interface — quickly add new lists or duplicate existing lists
Can hide in the system tray and be used with a hide/show hotkey
Cut/copy/paste entries from one list to another maintaining checked state
Paste entries in from the clipboard
Customizable list font
Sort checked items to top or bottom
Check all and uncheck all buttons
Always on top button

Frankly, sChecklist is one of those programs where you appreciate the simplicity of it if a simple checklist is what you're looking for.