Augmented reality tours in the UK

We have a historic waterfront trail walk, and we would like to bring that to life a bit more using augmented reality technology which can appear on their mobile phones as they follow the trail. The idea being that as the people walk along they can bring up images of what the area you used to look like, and the characters and things that happened in the area. Similar technology I guess to Pokemon Go.  Has anyone worked with or know of any UK companies that have create this kind of thing for a destination, using existing basic or emerging technology? If so, I would be grateful if you could email their contact details to me at john.gibbs@gosport.gov.uk 

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