Mobile Software Development

Looking for a CRM & App to be developed for a facilities management company. Will need it to be a CRM and also an App for our drivers. Track the whole journey of vehicles or at minimum on client sites. To link to accounting packages for invoicing purposes and reporting. To link to other 3rd party software and apps. To be able to evolve with the growth of the company. Must be developed in IOS and Android. Further details can be discussed.