I don't track all the time. I usually try to start tracking when I'm having lots of episodes or if I'm in an extreme episode, not because I need to write it down to remember it, but because handing a sheet of paper to my pdoc is easier than explaining everything. I don't use an app, I designed my own with number ratings for mood (-3 to+3 with 0 being baseline), anxiety and irratibility (1-10), and I also write down hours of sleep and meds taken, with a comments section at the bottom of each day so I can write down things that happen that may affect my mood.

It was pretty simple to set up, just a chart in Microsoft Word. I tried a line graph once, which looked cool, but numbers just work better for me.