They look like two categories in the App Store, and in practice they are two halves of one thing that most apps only give you one of.
What a mood tracker is good at
Speed and consistency. Tapping a face takes a second, so you keep doing it, and after a month you have a shape: the run of grey days, the drop that always lands mid-week. What it cannot tell you is what any of it was about. A chart of a hard month looks the same whether the cause was a job, a person or a flu.
What a journal is good at
Detail and context. It holds what actually happened, which is the part you forget fastest. What it is bad at is being read. A year of entries is a folder you will open twice, and the useful thing in it, the repetition, is invisible at reading speed.
The version that works
One record that carries both, so the writing has an axis and the mood has a reason. Then something that reads back across weeks, because that is the step that never happens on its own.
That is the shape Dayglean is built in. A moment is a mood tap with optional writing, so the fast version and the detailed version are the same entry rather than two apps. The calendar gives you the tracker view, a month of colour at a glance. The weekly Pattern Drop is the read-back: one specific observation from your own entries.
If you only want one
Pick by what stops you. If you never write because it takes too long, start with the tap and let the writing be optional. If you write plenty and get nothing back from it, the missing piece is not more writing, it is something that reads it.
Dayglean
A private journal for iPhone, iPad and Apple Watch. Tap a mood, write a line if you feel like it, and once a week it hands back one specific thing it noticed in your own entries.