How I Got to the App Store Top with a Simple Currency App

    In November, a rapid devaluation of the ruble began.
    This fueled interest in my application and all similar
    ones in the App Store.

Off topic edit: for those interested, unlike other budget apps/spending trackers my app actually is meant to be used by a family that shares expenses. You log your purchases as you go (this was optimized to be super quick), and your family can see how much money is left until the next refill period automatically. This was also out of necessity. I read on HN that the easiest way to get extra cash every month is to make a budget. Turns out, that's correct, and this is the easiest way to do it for me.

Here's the app, in case anyone was interested: https://itunes.apple.com/en/app/kurs-valut/id831528898?mt=8

The OP didn't set out to start a business, but this definitely is a good example of rather than looking for the next billion dollar startup idea just focus on building cool stuff to solve problems. Who knows, maybe this could turn into some kind of exchange rate information company.

ps: would love some support for multiple data-sources per currency: for instance in Argentina we've official dollars but since they're impossible to get we also have sidemarket "blue" dollars...

2) Work hard. Then again, pace yourself. Sleep dep is a bitch and counter productive.

3) Be lucky. Make something that lots of people want.

To be honest there's a lot more and the article is well worth reading.