If you haven't read Paul Graham's Startup = Growth yet, and you're running a startup, then you're missing some really important insights.
The short version (that doesn't do the essay justice) is: Startups that have 5%-7% weekly growth can do 12x - 33x in a year.
Here at WhereDat, as data geeks, we wanted a better way to track and plan our growth, we could do it in a spreadsheet, or use one that someone else already made, but we wanted an "app for that", so we built it.
This way you can track your growth and see your goal for next week with one hand tied behind your back.
It's very basic so we've open sourced it in case you wanna tweak it.
You can download it here: https://play.google.com/store/apps/details?id=com.wheredatapp.startupcalc