It is a 3-way communication for the best experience of contact tracing.
1) VISITOR/USER APP
who will select/act those checkin checkout when visiting places.
2) BUSINESS APP
where visitor will visit and select/act those checkin checkout.
3) ADMIN PANEL
where all data storing from who is visiting,where, when, for how long as well as details of the registration to communicate further both visitor and business. When someone visited a place and perform the application operation as checkin checkout then those checkin checkout details saved on visitor/user app, business app and admin panel.