SashiDo.io VS EssentialPIM

Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.

Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

OneSignal - Customer engagement platform used by over 1 million developers and marketers; the fastest and most reliable way to send mobile and web push notifications, in-app messages, emails, and SMS.

Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.

Parse - Build applications faster with object and file storage, user authentication, push notifications, dashboard and more out of the box.

Strikethru - Strikethru is a kind of to-do list notebook for managing work lists and staying updated with the important tasks.