**Convert Excel spreadsheet to Mobile App - Send me your quote**

Scope:

This is a straight conversion from Excel to an APP. Formulas are curently working on a spreadsheet but will need to be Hardcoded and converted to an App.
This is a Date & Time calculator where the user will have to select data from a pop up clock, calendar & drop down list.
This App will not appear on Play Store and therefore APK file will be shared directly to few users.
Some sort of usage control/licensing with expiry to be implemented (i.e FireBase) to allow Admin to set custom duration.

Note: if you also work with Apple products, please include your quote for similar scope.

Speadsheet & App:

Simple spreadsheet with 8 formulas to be Hardcoded (hidden & locked).
Data Validation (in a form of a drop down list) to be Hardcoded = 13 entries (Time Zone +/- 6hrs).
x2 cells with Conditional Formating Red/Green pending on specific formula results.
Total of 16 tiles to be displayed on this App & 8 of which to be interacted with (other cell/tiles can be locked from editing to user).
Out of those 8 tiles:
x3 will need a pop up calendar
x3 will need a pop up clock
x2 will need a drop down list (13 entries from +6 to -6)
Also,
x1 jpeg to be displayed on top of App
x1 logo for the App

Requirements:

This App has to work offline.
Admin via Firebase (or similar) must be able to change the period of validity in the app for all users or be able to reset the date of any user (by changing the value of number of days the app can run).
So Admin can keep track of date when the app was installed and then disable the functionality for the given device after a chosen period.
Once App expired, show a message: Contact ADMIN to reactivate.
To make things simple, when the app is installed and started for the first time, it will need to be connected to the internet at least once to get activated (Pop Up Message: Please connect to a network to activate).
So it can get the expiry date from the online database.
When a user has used the app for a set period (Admin to decide), in order to get the app reactivated, they will need to synchronise again (this will happen next time the app is started with the device back online).
Same if the user Uninstall and Reinstall the App, they will need to sync again.
Adding to this, Admin will need to get user's IMEI number so to keep track if the app is installed for the first time or more.

Looking forward to your proposal with a realistic completion timeline.
You are the expert and I will welcome any suggestions that will make this App elegant & effective.