Modular Android CRM App Development

I need a single Android application that pulls together everything our company now does in separate spreadsheets: sales, service, rental, dispatch and accounts. Each team must log in with its own credentials and land on a dashboard that only shows the tools relevant to that role (Sales, Service, Dispatch or Accounts).

Core modules -
•EMPLOYEE -ALL EMPLOYEE LOGIN WITH SELFIE AND LOCATION AND TIME , AUTOMATIC SALARY AND ATTENDANCE , LEAVE REPORT , OVERTIME REPORT, BONUS POINT, PROBLEM NOTIFICATION REPORTS,MISTAKE REPORTS, TOTAL ATTENDANCE REPORT

• Sales management – lead capture, customer follow-ups and daily activity logging , MONTHLY ORDER SHEET, ORDER ACCEPTANCE WITH ADVANCE REPORTS. DAILY VISIT REPORTS, MONTHLY VISIT REPORTS,
• Service tracking – ticket creation, status updates and technician reports , ENGINEER WISE COMPLAIN SOLUTION REPORTS, INSTALLATION REPORT, DISMENTALLING REPORTS, DAILY JOB CARD ENGINEER WISE, LABOUR MONTHLY REPORT, COMPLAIN SOLVING TIME REPORTS
• STORE - INWARD , OUTWARD , RENTAL INWARD, RENTAL OUTWARD, PURCHASE,STOCK REPORTS
• Dispatch DEPARTMENT –TRANSPORT ARRANGMENT, LR COPY ATTCHMENT, DRIVER ALLOCATION FOR RENTAL AND SALES
• Rental asset management – availability, hand-over history and return inspection logging monthly cycle , history card, RENTAL EQUIPMENT SHEET PARTY WISE, PARTY AND SITE WISE LEDGER, MACHINE NUMBER WISE LEDGER,
• Accounting – payment follow-ups and party-wise ledger tied to every customer record, cash and bill ledgers , credit system reports,CASH DEAL REPORTS , CASH AND BILL REPORTS,

Reporting
ALL REPORTS NEED IN PDF AND EXCEL FILE SO WE CAN SHARE WITH CUSTOMER AND NEED WHATS APP BUTTON FOR REPORT SHARING DIRECT TO CUSTOMER AND EMAIL SHARING TO CUSTOMER


Data flow & security
A shared customer database should power every module, yet access must remain permission based so users only see what they need. Login can be email/password for now, but the code should be ready for future single-sign-on.

Deliverables
1. Production-ready Android APK + web base and full Kotlin/Java source
2. Simple back-end (Firebase or a light PHP/MySQL API—open to your suggestion)
3. Database schema and API documentation
4. Short hand-off session plus 30-day bug-fix window

If you have built modular CRMs or field-service apps before, please point me to them when you reply so I can gauge fit quickly. Show More