Catalogue iOS App Build

I am looking to have a functioning shell of an iOS app built which will be based on a tab app. It will be used for a showcase of work and will need to have the home page, 5 separate collection pages and then a contact us section. The tab bar will need to have a custom button in the middle returning you to the home screen. In each of the collection pages will be a bit of text and then a selection of projects that when clicked on will take the use through to photos style screen where all the images from that project will be. The user must be able to scroll through the images, pinch zoom on them and be able to share them. This app must be able to be used offline so all images will be stored in the main file and it must be able to be used on both iPhone and iPads. I will be adding most of the image content myself as there is a lot, but would need a few stock photos added in so I can see the flow and how I need to add the rest of them in. I have attached images of how this would roughly need to look. Thanks for looking.