Development of simple mobile app (iOS and Android) for capacity planning

We manage lots of freelancers who work for us and do all the same task. In order to know how much everybody can do, they mail us their capacity (in minutes working time) and we insert those in a Google sheet. Rows are the name of the person, columns the day and the field are the minutes the person can work on that specific day. We would like to develop an app for this process in the future. The app should run on both usual platforms (iOS and Android). Key functions of this app should be: - Freelancers have login-data to get to their personal area - Freelancers have a simple profile in this personal area (name, address, bank account, skills, preferences) - Freelancers can change this login-data - Freelancers can input number of minutes of their capacity in a calendar (with optional comment) - Freelancers can update/change/delete number of minutes they have put-in before - Automatic push notifications to freelancers following specific rules (reminder of upcoming capacity, reminder if no capacity has been inserted for a few days) - Back-End: Overview on capacities which have been reported by the freelancers (including comments and skills/preferences from their profile) - Back-End: Possibility to send push-notifications to freelancers (all or only those with certain skills) - Back-End: Possibility to make news-ticker showing up when freelancers log-in - Back-End: Statistics on capacities reported and log-ins. - Back-End: EMail notifications when profile data of freelancer has been changed - Back-End: Download as csv of all/selected freelancer profile data and all/selected capacities - News screen with information on upcoming events etc. which can be updated in the backend