Web & Mobile Ticketing Tool

I need a straightforward service-ticket system to manage requests for our medical-equipment company. It must run smoothly on both web browsers and mobile devices so that my office staff and field engineers can raise, view, and close tickets wherever they are.

Core flow I have in mind
• A customer or staff member logs a new service request, entering the device ID, issue description, and photos if necessary.
• The ticket is time-stamped, given a unique number, and automatically placed in an “Open” queue.
• I should then be able to assign it to an available engineer, update its status (in progress, on hold, closed), and leave internal notes.
• The requester receives push or email notifications at each stage.
• A simple dashboard should let me filter tickets by status, date, or serial number and export basic reports for compliance records.

Although I have not finalised every permission level, the solution should be flexible enough to accommodate common roles such as administrator, technician, and possibly customer log-in later on.

Preferred deliverable
• A fully functioning web app plus a companion mobile experience (either responsive web or a lightweight hybrid app).
• Clean, intuitive UI—nothing fancy, just practical.
• Source code and brief hand-over documentation so my IT assistant can handle routine upkeep.

Please outline your proposed tech stack, milestone plan, and any similar tools you have built before.