I had an app on my phone that was a mood tracker. A really simple one, you chose out of 10 faces, from “the worst” to “ecstatic” and it would log it in. You could also write tags and then go back and see what tags were associated with good or bad moods. For me though, it was just the act of regularly (every hour when I was in an acute episode) going and logging my mood. A way to split the day into manageable sections, and sometimes it was even encouraging to see that there had been some improvement throughout the day.