Table 2.

Key findings from our thematic analysis.

Research question	Key findings
Why do people use these mood-tracking apps?	Life events which triggered stressful or challenging moments motivated some participants, while others sought out mood tracking for greater self-awareness and self-reflection.
What do people find useful about the approaches that mood apps take to entry and review?	Most participants preferred data entry screens with fewer options, but which supported the ability to customize what they logged. For data review, participants wanted to be able to compare a logged mood with previous entries, preferring graphs and feeds which enabled this.
What do people find challenging about the approaches that mood apps take to entry and review?	The burden of mood tracking led participants to track once per day (or less often), and they questioned how well that mood reflected the moments they did not track and whether visualizations of that data were representative. They also found it challenging to identify if or how their mood improved based on the trends they observed.