Cannot get it to work

It fails but all I get is a rose coloured bar

And if I choose Upload Installation Package, it just loops around as though its not recognised.

OK Email me backend access, or post here as confidential information.
I'll have a look.

Info as requested

When you have taken a look (assuming you can resolve the issue), I will need to apply it to my main/live website, so will need to know how it was achieved.

Not sure what you did but it installed fine on your setup , on the first try.
Obviously this app had allready been set.

What you need now is make sure users, at least hosts, have cooridnates set using their address field in their profile edition
(maybe the country field gets useless then)

Once a user il located, he becomes a 'host' and other users can checkin at that hosts place.
When clicking the checkin button or scanning the QRCode, the component will compare the distance betwen the host and the visitor's browser (user has to accept to share location).

It seems to work perfectly on your site except from the icon-set that seems to conflict with another one.
I'll try to solve this for you.

Does it help ?