Android mobile app

I need a new Android App developed siilar to https://play.google.com/store/apps/details?id=com.odoo.OdooTimesheets but allows Odoo portal users. The branding will also have to be consitant with our internal systems and not Odoo

*** Important information IT MUST ALLOW PORTAL USERS ****
*** It must interact with https://www.odoo.com/app/timesheet-features ** on Odoo 15 Enterprise located on self hosted server

I WILL NOT SWITCH FROM PROJECT TO HOURLY