Build me an app

I would like to build an app for my labour hire business. I will need my clients to be able to make orders for labourers and/or tradesmen using the app. I will need admin access which allows me to send jobs to my employees which they can either choose too accept or reject. i will need to have a time sheets feature where employees can record their shifts and have approved by the site managers.

app must be functional on iphone and android.

I will be providing drawings to make this task easier for you and can provide more information as requested.