Ponit of Sales (cashier system) base on Cloud

our application is Ponit of Sales (Cashier system base on cloud) using by coffee shops and small retails. already Application published on google play,

- simply user access to store by using username and password, (first logging should have internet).
- once login successfully the application getting request to server for all data related to store from server and then server send response with all details.
- Application save all data locally in case if there any interruption with connection the application can work offline and keeping system running and saving new data locally until application is back online again then application pushing New data saved during offline mode to server.
- if application is online system keeping sycornising with server for each order.

however I'm planning to add some new feature as below

* open new Feature on main menu (return stock) .. (UI, API.)
* open new Feature on main menu (orders view).. (UI, API)
* allow kitchen printer printing only products related to same section (category)
* Fix the UI of the application ( Responsive UI ), should be flexible with all HW ( IOS APK Windows )
* export IOS APK Windows
* send HW Mac with user name and password for first login
* notification
* auto printing if there any Order coming from online store
* adding order status on running order list . Ex: closed.. on kitchen

New features should follow the current design such as
* working online and offline mode,
* save some data locally in case of loose connection
* etc.

one condition: the freelancer how will handle project should have cashier printer for physical test (we will not pay fees for this HW)