Digital Attendance & Vacation Tracker Building

Subject: I need to Build Simple Digital Vacation & Attendance Tracking System (iPhone + Web)
Hello:
I am looking for someone to help me move my manual Excel vacation sheet into a digital system that employees and managers can use easily from both iPhone and a web browser at affordable price.
What I need:
Employees log in and submit vacation requests digitally.
Managers can review and approve/decline requests.
A dashboard/summary view that shows:
Who is on vacation
Who is on the road
Who is at work
Who is sick
etc...
The system should be simple, affordable, and user-friendly.
Mobile and web access is essential.
Provide some basic guidance/training once the system is ready.
Optional (nice to have):
Notifications (email or app) when vacation requests are submitted or approved.
Export or reporting function (monthly/annual summaries).

Please let me know:
Any platform is ok (Google Sheets + forms, Airtable, custom web tool, or another approach).
Your estimated timeframe and cost.
If you can design it to scale as our team grows.

Thank you,
Eyad Shi