I want to point you to TAWNY. It's an emotion diary app for all iOS User. I use it for several months and it's very useful to enter its own emotions and it's also fun to see my emotions of the last week/month etc.
The developer team is already honoured by the "Munich digital award" in 2016 -->tawny.ai
I like the idea and I also have a Microsoft Band 2 (this is the point I find this app in the first place), but you can also enter emotions without the band and then you have the utter quantified self.
Here the link (https://itunes.apple.com/us/app/tawny-emotion-tracking-gef%C3%BChlstagebuch/id1215799617?mt=8), perhaps you also get used or rather addicted to this app
This is my pocket diary, where I not only enter my mood, feelings and emotion, but also my thoughts and activities.