I used to track on Mood Tracker - Help for depression, anxiety, and bipolar disorder but haven't for a long time. It at least used to have a free option as well as a fee-based premium option. It appears that they've added additional features since I used it last. They also have special versions for different mood-related conditions, including bipolar disorder. The free version I used to use allowed multiple level mood ratings and even the ability to mark mixed states, also anxiety or irritability, menstruation, medications, sleep, and maybe one more thing. The current premium version offers tracking/features of all of the following (copied from their website):

Track Unlimited Customizeable Measurements:
Core Mood
Mixed Mood
Anxiety
Irritability
Alcohol Use
Recreational Drug Use
Sugar Amount
Significant Morning Event
Significant Afternoon Event
Significant Evening Event
Sleep Hours
Sleep Quality
Followed Medication Plan
Exercise Quality
Menstruating
Water Liters
Area Charts
Summary Bar Charts
Medications, Supplements, & Exercises
Email Reminders
Text Message Reminders with Reply
Wellness Team - Friend & Mentor Roles
Journal Entries

A lot, right? I assume they still have a free option. If so, I don't know if it changed. I also believe (not sure) they have an app. If so, I know nothing about it.

I haven't tracked for a while mostly because my moods haven't fluctuated much for a while. Plus, when they did I sometimes found myself having to go back and correct because of lack of insight or episode denial. The latter is especially common for me when it comes to depression or mild mood elevation.

I wonder what their "Wellness team - mentor/friend roles" is about. It appears that their Premium option is just under $10 per month.