Build me an app

Users:
1.owner
2.customer
3.salesman(DSO)
Problem Statement:
This application is mainly for confirmation purpose.In this app, different DSO’s can have
different logins,each DSO has a different set of customers. Payment confirmation should be
done by both DSO and customer , this confirmation message has to be sent to the owner. There
are 3 kinds of payments :
1.neft
2.cheque
3.cash
Whenever a DSo reaches the customer and collects any of the above payments , the customer
has to confirm that he has given money to a particular DSo by verifying with otp or pin or any
suitable verification. Whenever DSo receives payment he also has to accept the payment that
he has received a certain amount from a particular customer on a particular date and with the
receipt number ( will present in physical receipt book) . Once the above process is done, Owner
receives the message that a particular customer had given a certain amount on a particular date
with the receipt number included to the particular DSo.
Requirement :
App need to be installed in android mobiles.
App should be secured enough that no one can manipulate it.
Have to respond when any kind of bug is detected in future.