iPhone: Tracking your daily activities over a long period can help you figure out what changes you need to make to be happier. You could fill out this one-minute form every day, but if you want something similar on your iPhone, then OptimizeMe is what you need.
At its core, the app is an activity log. When you do anything, you put it in. There are four broad categories—health, creativity, pleasure and routine—each of which have lots of sub-categories, from how much you walked, what you ate, whether you watched TV and if you had sex. OptimizeMe also integrates with the Moves app if you have that installed, easily tracking your steps and runs. I suggest you get that because you aren't going to remember to switch on OptimizeMe's tracker each time, but Moves just works in the background to make it happen.
The cool part about OptimizeMe is the analysis it gives you later. All of the data you logged is turned into beautiful charts with a lovely correlation feature where it takes data from one activity (like sleeping) and shows how much it affects another activity (like your overall mood). Initially, I got nothing—but just three days into the app, there was a distinct correlation between my dinner habits and sleep habits. I spoke to a friend who has been using the app for a longer time and his iPhone has a lot of these great correlations now.
But OptimizeMe is still dependent on you inputting the data accurately and honestly, it can't work without that. For all the smarts—it even has a Siri-like assistant named "Ari", who is just a gimmick—it is reliant on your regular updates, so I'd recommend setting a daily reminder at night to update the app.