Build me an IOS and Android mobile device social media style app

I'm aiming to launch a social media app for the residents, business and community groups for the Town where I live. Required features to include user profile page with hashtag, @mention, likes, follow etc Users to be able to post text, pics, GIF and video on community newsfeed(s) where all users view all posts on the community feeds rather than an algorithim dictating what users see on their timeline. May need more than one feed/wall so there is a dedicated community buy and sell feed and a feed specifically for local estate agents to post their properties for sale or rent. A key feature is an events calendar so users can populate the calendar themselves to promote their events. Ideally with space to post a supporting poster/pic. This would make it easier for users to promote and search events by date rather than scroll through a Facebook page style newsfeed to find events. I'd like the app to be free from external advertising. Subscription based for users. There needs the functionality to have local business listings (pages) listed by category eg. Shopping, eat and drink, business, leisure. Preferably a feature that allows to seperate business users from residents profile so a slightly higher subscription fee can be obtained from businesses. Their subscription would therefore result with them having their own business page listed in the relevant business zone I.e. shopping, business, eat and drink etc. Ability to allow users to live stream would be great though not essential if this would add a significant increase to the cost of the build. I'd like ability to allow hyperlinks to existing websites on the internet though keep these sites contained within the app when opened. Ie. No ability for users to then search other external websites via their web browser. I am not experienced in app development though my area of expertise is communications and people engagement. My vision is to provide and manage a community media app that supports and engages all of my local community. An app that supports local businesses by offering an alternative to the giant global social media platforms. Where business and social and community groups can promote themselves to their primary, loyal and local customers/audience. I have identified a UK company specialising in community app that can be customised with my own branding, include as many feeds as I require etc for an on going fixed monthly or annual fee. I do feel it is best for me to explore all possible options and consider commissioning an app for an agreed cost. Grateful for advice, consideration and estimated costs and timescales involved to build the app. Fraser Park-Jones