I don't really know what I was expecting to get out of a mood tracker when I downloaded it. Cool graphs, probably? After over three years of using Daylio, I do have some pretty cool graphs, but I don't generally get much benefit out of looking at them. It turns out I do still get a lot of benefit out of mood tracking, and here are two concrete ways it's helped me.
I configured Daylio to send me a reminder four times a day: 8am, 12pm, 4pm, and 8pm. Throughout the day, I'm reminded to ask myself "how am I doing right now?", and I take a moment to notice how my body feels (relaxed? tense? tired?) as well as my emotional state (worried? upset? excited?). The more I've practiced paying attention to how I feel, the more often I've noticed when my mood shifts without even needing a reminder.
Being aware of my emotional state helps me in several ways. It gives me a chance to intervene early if I'm starting to get upset, such as doing a mindfulness exercise to stop myself from entering full-blown panic. It also gives me the information to be able to communicate early and often to the people who can support me. Noticing my emotional state also helps me recognize correlations -- I'm often cold when I'm anxious, happy when I'm in the sun, unmotivated after watching a lot of TV, and excited when talking to particular friends.
Even if I used a mood tracker that didn't store any data, I think using it would still bring me most of the benefit. Building the skill of noticing my mood has dramatically improved my ability to regulate my mood.
I've written elsewhere about how I value zooming out:
Recognize the wider scale of things to make the present moment less scary. Long-term trends are generally more useful than short-term trends. My life, mood, relationships (everything?) has its ebbs and flows and if I'm too zoomed in, it can be exhausting to react strongly to every small change. Even if I've had a rough time for a while, I can zoom out and see similar patterns in the past where I eventually felt better, and trust it'll get better again.
Using a mood tracker has helped me feel more confident in long-term trends. When I'm feeling bad, it can be easy to feel like things have always been bad and will never get better, and when I'm feeling good it can be hard to notice unhealthy parts of my life.
Instead of looking at Daylio's graphs with the daily averages, I like to skim through recent mood entries. Right now I can see that I've felt regularly bad for months and not just the last few days, which is a reason to try to change something. I can also see that most days have moments when I feel pretty good, so I can usually trust that I'll soon have a moment of clarity and energy and inspiration.
Recently, I've also been tracking my mood around specific topics, just in a spreadsheet, to figure out how it's specifically affecting me. For example, is work fine most of the time, or am I unhappy at work most days? Is a friendship mostly bringing me happiness or stress? These things have their ebbs and flows, and it can be hard to judge if something is worth holding onto or if it's time to hit da bricks (or dramatically change it, or take a break from it). I don't yet know how I want to use this data, but even just paying attention to how I feel has already felt helpful.
I often think back to a conversation I had with someone who had once tracked data on dozens of aspects of their life. They told me that over the whole time they tracked this data, the habit that helped them the most was journalling. Just noticing what was going on, writing it down, and skimming through old entries. No complicated data, no fancy graphs, just taking the time to be aware. And after entering my mood into an app 3000 times, that's been the biggest benefit for me as well.