App development - Cobalt Sign Symbol

The Chemistry of Apps

We like to take a meticulous approach to creating gorgeous apps,

starting from just an idea to product launch.

#iOS   #Android

Cobalt Sign - Mobile App Development - Team at office
Cobalt Sign - Mobile App Development - Hello App
Cobalt Sign - Mobile App Development - Team at mDevCamp
Our Style

Engineering & Passion

It is all chemistry. We enjoy building mobile apps and staying up to date with the latest news & technologies in app development. The languages of our choice are Swift, Kotlin/Java and React Native.

Our proven chemical formula for the best product = passion + attention to details + UX + tech skills + reliable team + good communication

Our Values

Teamwork & Good Times

We care a lot about team spirit and enjoying time at the office.

Contributing to the community is important for us, we organize free app development courses & we develop pro-bono apps for NGOs.

Cobalt Sign
Cobalt Sign - Mobile App Development - Hello App
Cobalt Sign - Mobile App Development - Team

Our own app,
“Ready Set Holiday!”, has over 2 million downloads and got
mentioned in The Telegraph.

We love it →



Ready Set Holiday! - Stylish travel app

International Awards

We always love a good challenge, enjoy taking part in competitions and, of course, receiving awards.

Samsung Gear App Challenge

We created a wearable version of our Tea Cup app designed for Samsung Gear 2. It was one of the winners in Round 1 of the Challenge.

Nokia Developer Champion

Awarded to Oana Csertus in May 2013. “Nokia Developer Champion is a recognition and reward program for top mobile app developers from around the world.”

Fast Track to the Mobile App

App design & development competition by Core77 and Microsoft in November 2011. Our app, 1tap2send was one of the notable finalists.

Imagine Cup “Rockstar”

“Windows Phone Rockstar Award” 2010. We reached the top 10 with our app, Hawkeye, a travel trails app, that organised your photos and created a map trail.


Brilliant and intelligent team, precise, professional and extremely on-time, transparent and very friendly. Was a very pleasing and professional collaboration.

Reza Paya, CTO ARMNet

We love working together with Oana and Arthur from Cobalt Sign. They are highly skilled experts for mobile platforms and combine great UX design and coding skills.

Simon Schweigruber, CEO - Dream Production AG

Cobalt Sign delivered professional results within a very short time, which helped us meet the deadline for a product-launch. In addition to the professional results of the accomplished work, we especially want to highlight the quick understanding of our requirements and the structured, professional way of working.

Mark Voorboom, Product Manager - Stb Automatisering & Advies BV

I've had the pleasure of working with the Cobalt Sign team on a few projects and I'm looking forward to working with them again. Using a clean and structured project management approach, oriented to getting things done, they were able to deliver high quality work on amazingly short deadlines, while leaving out the stress and chaos that usually arises in these situations. Did I mention they consistently create beautiful and responsive UI's?

Andrei Marinescu, CTO - Appscend

Take a look at our portfolio to see more of our work.

See portfolio