link to launch external link
<!-- https://developer.apple.com/library/ios/featuredarticles/iPhoneURLScheme_Reference/MapLinks/MapLinks.html -->
<a href="maps://?q=dallas" data-rel="external">iOS launch in apple maps</a>
<!-- https://developers.google.com/maps/documentation/ios/urlscheme -->
<a href="comgooglemaps://?q=dallas" data-rel="external">iOS launch in google maps</a>
<a href="geo://0,0?q=dallas" data-rel="external">Android launch in google maps</a>