We need to create a job board app (I think we can call it job board) where people can offers works or/and services in that exactly moment they are available, do you know Uber? Uber offers driver services in that moment, so if you need a service you select the category of the service you need and the time you need (even now or in 30 minutes) and then the website will find the service you need for the time you inserted and you see people around you in your location, that offer the service you need, on the map near you and you can select the person you wish to get your service.
So if I were a cleaner, and I have 3 free hours during my day, I put I am available in that area to work for those 3 hours for 10$ (just a sample).
Instead, suppose I need a nanny for my kids in 30 minutes from now, I search my postcode, I select the category of “nanny & baby sitting” and on the map I will see the best option/person available in 30 minutes near me and then I can click on each of the options to see their reviews or description or if they are female or male and then I can book the service. The available person has got her own profile with description and informations, and by her account she can update when she is available to offer that service so she can appear on the map (as uber does with taxi driver, they must give their availability for that time).
The client will pay the book fee after the first time (first time will be free as trial), instead the workers will pay a monthly fee after the first month of trial, in the web there are already many plugins and themes that offer a service similar to this link booking I think in the theme there is already a book service or something like that, about the membership for workers, there are many plugins for membership ready to use maybe they need a little edit to be only for workers.
The app would need the website where to download it, the app needs to be for android and also iPhones.