I use an iOS app called, Reporter (http://www.reporter-app.com/). It prompts you with push notifications to answer a set of custom questions throughout the day- Are you looking at a screen? Who are you with? Where are you? How many cups of coffee have you had?

The reports also capture "background" data using the phones sensors: number of steps, temperature, volume, elevation, phone battery, etc.

Its great for lightweight tracking and all the data can be exported in CSV or JSON formats. Reporter can definitely help you track sleep hours, food eaten, and productivity (weight and body fat % can also be captured).

I wrote an article about the 500 reports I've captured over the last 107 days: https://medium.com/p/c4454b9d8456