Mobile App (iOS only) for job tracking and invoicing

The employer is looking to create mobile app for iOS for a job tracking system for maintenance jobs. The employer will need an Admin portal to manage users, jobs and all other entities, and to view dashboards and get an overview with ability to drill down into information on the current status of all jobs. The core features of the project: 1) Mobile App (iOS) - to be used mainly by field staff ([login to view URL]) --User Login and Authentication --Database of clients with their relevant data fields (ie. contact info, history of booked jobs, etc) --Creation/Scheduling of jobs - after client calls the mechanic, the mechanic can input the necessary information into a form, which would create a job that is connected to a calendar (could be integrated ie. Google calendar) --Tracking of jobs, job/service history, how much labor was involved (hours), inventory of parts, and other related data --Track job price, labor hours, parts used --Ability to output an invoice with costs broken down by labor, parts that can be sent to the client via email and also stored in the system database --Ability to have a set of standard forms that can be signed digitally and stored in system database 2) Web Admin Portal --create, view, update, and delete users, jobs, parts, all entities --Dashboards to visualize jobs --Ability to generate Reports --Track inventory --Customer profile/dashboard for easy to understand overview of customer’s information, with the ability to drill down and see details as needed --Google calendar integration **In your proposal, comment what tech stack you are going to be used. The employer is technology agnostic - they do not mind which programming languages are used. That said, the technologies used should be modern, well supported, and the code should be clean and bug free, and follow DRY principles.