'Mood Monitor' is the only app specifically designed to monitor for depression in people taking the medication Isotretinoin for acne. Given that low mood and depression can sometimes be gradual and insidious, it is medically recommended that those using the medicine Isotretinoin have their mood assessed throughout the course of the medication. Totally independent of pharmaceutical industry, 'Mood Monitor' helps address the issue of Isotretinoin and depression in a number of ways. Firstly, there is an up to date literature review and discussion about this potentially serious issue. Secondly, there is a short, medically validated questionnaire that measures mood level. There are prompts to repeat this questionnaire episodically throughout the course of Isotretinoin with objective reports about mood level and warnings if there is a concerning trend towards depression. A copy of all results is automatically emailed to parent/carer/partner if requested. 'Mood Monitor' is the simplest and most convenient method of alleviating fear regarding the side effect of unrecognized depression whilst taking Isotretinoin.