Gone - An ephemeral to-do list
Kissflow - Kissflow is a workflow tool & business process workflow management software to automate your workflow process. Rated #1 cloud workflow software in Google Apps Marketplace.
Streaks - The to-do list that helps you form good habits.
ProntoForms - ProntoForms is a mobile business solutions application, converting paper forms onto any tablet or mobile device.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Nintex - Cloud-based digital workflow management automation platform