SimplePractice - With SimplePractice, manage your notes, scheduling, and billing all in one place. Conduct secure video appointments with Telehealth by SimplePractice.

EssentialPIM - EssentialPIM is a free Personal Information Manager that keeps up with the times and lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.

TheraNest - Mental health software for psychologists, social workers, therapists, counselors.

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

drchrono - An EHR built for your specialty:

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