Enhance Existing PowerApps Timesheet App

We need an export PowerApps developer to enhance an existing PowerApps app. We want to add additional features and functionality. The initial features/functionality I am looking to add are: 1. Enhanced User Management 2. Ability to add Expenses per line 3. Enhance the ability to change dataset for admin users i.e. projects (Currently done manually through SharePoint list) 4. Ability to pre-populate on-screen data based on the user logged in or based on the the project selected. I have attached two screenshots so you can see the current layout of the app. You must have a proven track record and will to show your ability. I am looking for long term partnership.