We need to Rebuild a Simple PhoneGap Application

We currently have an app that facilitates employees clocking in on android and iOS devices. The application is built in PhoneGap and hits a well defined API to get it’s data. Currently the app is giving issues on older versions of iOS namely iOs 9.3.5. The application uses jData and JQuery Mobile as well as syncfusion UI controls (their ej libraries). This combo of technologies do not seem to work well and slows down the app. We require the developer to rebuild the app from scratch to ensure reliability and a smooth user experience. The app is small and simply needs to do the following - Store offline data to maintain usability even when 3G GSM (Needs to work over this and WiFi) connection is down - Sync with the API to register check-ins/outs, update employee data - Display loading screen that is displayed only on a fresh install that allows the user to set the URL that the application will use as well as the Device ID - Provide a main screen that allows users to enter their username and PIN (4 digit code) to check in/out - when entering their username the text box will show all relevant users (predictive) so that the user can quickly get to his user name - prevent the user from entering a username that does not show up on the predictive list - Provide an Admin screen that shows all users logged into the current boat and allow the admin to force check them out directly if needed. - The admin screen will allow updating of the URL and device ID as well - The Admin screen will only be available for users that enter the Correct PIN AND have “Admin” somewhere in their username - Ensure that the app is properly tested on iOS 9.3.5, latest iOS and latest android - All data connections and security tokens can be pulled from how the old app works - the source will be uploaded. You will be required to look at this to ensure you define and use the web api correctly. - Technologies that should be used in the rebuild will be the latest PhoneGap, AngularJS and what ever Library the freelancer recommends to replace the JData library - Relevant animations for a smooth app will be needed to show when the app is communicating with the server, when errors in communication happens, when the app is in offline mode etc