Checkly - Fresh API monitoring and Site Transaction Monitoring. From one great dashboard.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Checklist Generator - Create checklists for free and host them wherever you want.
TaskPaper - Plain text to-do lists for Mac
listshare - Create beautiful, interactive lists to share with the world.
Magnetic - Magnetic is an all-in-one agency management software built for productivity.
Listshare the group list app is great as a simple solution for any type of list. Everyone gets updates instantly and we've even used it at work. Check it out. Great for families too which was our first use.