Case study · my own product
Cestiq: from a student app to a school portal.
I designed and developed Cestiq as a connected product for students, instructors and school administrators. The mobile app and web portal serve different tasks while working with shared data.
Author: Jan Kimla · Status: available on iOS, Android and the web · Updated 23 October 2026
This is not a customer testimonial or independent review. It describes my own product and does not establish business outcomes for other companies.
The problem to solve
A student preparing for the Czech driving test needs to understand their weak topics. An instructor needs visibility without asking each student to send results. An administrator needs clear records of people and access. These needs led to a shared model with several focused surfaces rather than one overloaded screen.
The surfaces I connected
Students in the mobile app
Practise questions and take mock tests, then review results and the topics that need more work.
Instructors in the web portal
Follow assigned students’ preparation. The useful outcome is a readable overview, not a raw list of database records.
School administrators
Manage students, instructors, invitations and licences. The portal also needs to be usable on a phone.
A shared technical foundation
Flutter for the mobile app, Firebase for authentication and data, server functions and a web portal. The surfaces work with a shared model.
Lessons for business software projects
Multiple surfaces do not mean disconnected products
The mobile app and administration solve different tasks but must agree on users, relationships and results. Data and role design therefore belong beside interface design.
Permissions extend beyond the interface
Hiding a button is not sufficient separation of roles. Systems like this need server-side access rules designed and tested alongside the interface.
A useful overview starts with the user’s question
Instructors need to know whom to help and what to work on. The dashboard should support that decision, not merely display every available metric.
A demo is different from live operation
The public demo preserves the original administration interface but uses a fictional school and local data. Real invitations, payments and remote AI requests are not performed.
What you can verify yourself
- Cestiq product website
- App Store · Google Play
- Original administration with fictional data — open the demo
Cestiq supports preparation for Czech tests. It does not replace statutory school records or accounting, and it is not evidence of compatibility with other countries’ driving tests.
Does your business need connected workflows?
You do not need to work in education. Similar needs appear wherever different users share data: a customer and job manager, a participant and tutor, or a client and service team. I scope the solution around your workflow rather than copying Cestiq.
Business software development →