Know me better Hire me


Hi, I am Jonathan and I sketch, develop and publish mobile apps. A total of 6 million people downloaded my apps so far. My best selling app is a geography game called Where is that? which helps children and adults to learn about the world.

During and after my Master in Business Administration I worked in Investment Banking at Dresdner Kleinwort, Goldman Sachs and Commerzbank. Eventually I decided to turn my hobby since I was 14 into a business and quit the banking world.

I now do what I love and that's what you can do best. I have the freedom to travel the world with my wife, who is a business consultant. That's were I collect my ideas for new apps. My approach as an Indie developer is to start with a great Minimum Viable Product (MVP) and then take the successful ones to the next level.

SAP, Walldorf
Working Student
Dresdner Kleinwort, Frankfurt
Goldman Sachs, London
University of Hamburg
Master of Business Administration
Commerzbank, Frankfurt
Investment Banking
2011 -
Jaysquared, Hamburg
Indie iOS Developer

What i do

I sketch, design, develop and publish mobile apps.

Native Objective C

I develop modern modular apps in standard Objective C with code and UI test automation and continuous integration.

Intuitive design

I am not a designer, but I know how to craft a simple and intuitive app interface with the help of outside resources.

App Store Optimization

I optimize the presentation in the App Store with eye catching screenshots, a compelling description and optimized keywords. Try searching for geography in the Apple App Store.

App Analytics

I evaluate which elements of an app are used and what to focus on in further development. That's user demand driven development and the only path to success.

Million Downloads

monthly active users

Top 10 in countries


This is a showcase of some of my current projects.

Latest Blog Posts

In my blog I write about learnings from my work as a developer.

App rejected because of a Game Center Bug

Ever app developer knows the horror of being rejected by Apple. There are tons of legitimate reasons, but from time to time, it just happens without your fault. It happend to me twice in a row because of a bug in Apple's Game Center.

Read More

How I pushed breaking changes to my iOS app without risking a sh*tstorm

My bestselling app is a geography game called "Where is that?". It's on the market since 2012 and in 2014 I was thinking about a fresh version with a new technological platform and new game mechanics. But I was scared of a shitstorm, if I published an update with breaking changes. And this app pays for my living. So I thought of a new brand called "Geo Arena". It had a revamped singleplayer mode and a brand new multiplayer mode. It received good ratings and I thought I could shift users from "Where is that?" to "Geo Arena", but that didn't work out.

Read More

My accounting is now automated and I love it

Accounting is my least fun part of being an entrepreneur. It's a repetetive task and perfect to be automated. I have around 20-30 different recurring bookings. In the past I used a tool called Debitoor, which was pretty decent, but still has a long way to perfection and some nasty bugs, which prevented the automatic tax reporting for me.

Read More


Feedback from my users in the App Store.


Where is that?

I've learned so much with this App. It never crashes and every version fixes the minor bugs. The best games are those that teach you something, and even more if they're as competitive as this one. It's important to learn geography, because there are people living in each of those places who must not be ignored.

Marty's Genius

Where is that? / What is there?

I own hundreds of geological apps, and this is one of the BEST, might be the very BEST of all!!!! I love that this app includes the cities of various countries, in addition to just about everything I need to learn and really know the location of the countries and capitals. I love both Where is That? and What is There? Perfection!!!!

Contact me

Jonathan Hillebrand

306/25 Nott St
Port Melbourne, VIC 3207