It sounds like you're developing a comprehensive employee management app with features like clock-in functionality, location tracking, expense management, and approval workflows. Here's a breakdown of the process and features you've described:

1. **Admin Setup**:
- Admin creates employee accounts with unique IDs and passwords.

2. **Employee Login**:
- Employees log in using their IDs and passwords.

3. **Clock-in Functionality**:
- Employees can click on a "Clock-in" button to record their work hours.
- The app captures the current location of the employee when they clock in.

4. **Location Storage and Retrieval**:
- When an employee clicks "Clock-in" again, the previously stored location is sent to the admin.
- This could involve storing the location data securely and associating it with the employee's account.

5. **Shared History**:
- Employees can view their own clock-in and clock-out history.
- Admin can access the clock-in and clock-out history of all employees.

6. **Expense Management**:
- Employees can attach expenses to their account.
- They can update the name of the location where the expense was incurred.

7. **Expense Approval Workflow**:
- Admin can approve or reject expenses submitted by employees.
- This likely involves a notification system to alert the admin of pending expenses.

To implement these features, you'll need a combination of frontend and backend development. Here's a general approach:

- **Frontend**: Develop a user-friendly interface for both employees and admins to interact with the app. This includes screens for login, clock-in/out, expense submission, history viewing, and location updates.

- **Backend**: Implement the server-side logic to handle user authentication, data storage, and business logic. This involves storing employee data, clock-in/out timestamps, location data, expense details, and approval status.

- **Integration with Location Services**: Utilize location services provided by the platform (e.g., GPS on mobile devices) to capture and store accurate location data.

- **Security Measures**: Implement security measures such as encryption for sensitive data (e.g., passwords, location data) and access control to ensure that only authorized users can perform certain actions (e.g., approving expenses).

- **Notification System**: Implement a notification system to alert admins of pending expenses or other important events within the app.

- **Testing**: Thoroughly test the app to ensure that all features work as expected and handle edge cases effectively.

By following this approach, you can create a robust employee management app that meets the needs of both employees and administrators.