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How to make 550k users help with troubling phone calls



CallerSmart is a telephone number directory created by its own users. Our work in this project started from mobile development, but we ended up delivering on mobile and web application. Together with our client David Crane, we’ve built a tool that makes phone communication safer and easier to manage.


Mobile development, App development, Project Management


Web, iOS

ios development

The purpose of this product leaves no doubt why we started off with a mobile version - it is the most convenient way to report unsolicited phone calls. After CallerSmart’s successful launch on App Store, we are responsible for the product maintenance and further development.

Web Development

Thanks to starting up with the iOS app, we were able to develop the product in a mobile-first approach. The plans are that the web app will serve all the functionalities of the smartphone app. At this point, we’re fully responsible for front-end as well as back-end development.


During the development of the mobile app, David took our collaboration to the next level and asked if we could take care of the overall app backend. We were excited to take on a new mission!

Key functionalities

To let users get the most of CallerSmart, we needed to build 2 core elements: high-performing data search and engaging features both in terms of generating and utilising the content of the app. Here are the solutions we came up with.

Callersmart app screen

Phone lookup in a snap

Basically, CallerSmart serves as a reverse phone lookup - it connects personal or professional details available online (such as: name, workplace, location, etc.) with given phone number. The app uses 4 external data sources to find as much information about any number as possible. Every user can add and check whether they are called by spammers, scammers or other potentially dangerous individuals.

Callersmart app screen

Gamification for active users

The app is frequently used in stressful situations such as cyberbullying. To help the user deal with the difficult situation, CallerSmart was designed with supereasy flow, fun and engagement in mind. Take such features as:

  • Caller IQ
  • Smart Badges earned with Caller IQ growth
  • Trust factor to help identify unwanted callers
  • Funny classifications, e.g. Heartbreaker, Drama Queen or Prankster

Further development

After Callersmart's successful launch, we are responsible for the product maintenance and further development.

Here is some of the results:

550 k

registered users

150 mln


23 k

average monthly user growth

4,5 mln

lookups and counting

10Clouds is phenomenal at hiring talented Polish engineers, particularly the ones who specialize in Python. We think of Maciej and his team as our CTO.

Brian david crane

Brian david crane

CEO at CallerSmart

Case study image


Branding, UI/UX Design,
Web Development

Case study image


Design, Web Development, DevOps

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Gareth N. Genner Photograph

Gareth N. Genner

Co-Founder of Trust Stamp


We needed a partner who could take on our idea, and make it real. 10Clouds bring so many different skills. We feel that every member that’s involved in the project is a member of our team.