How to Make URLs to Open Gaia GPS at a Coordinate
You can create gaiagps:// URLs that open Gaia in a couple of ways.
When you upload a track via the email importer, Gaia emails you a link to import the track. You can also extract these links from the email and post them on your website if you wish.
Here is a link to one of Halfmile's Pacific Crest Trail track files, that will open Gaia and import the track:
You can create a URL that opens Gaia GPS to a given lat/lon and zoom. Here is an example you can click from your iPhone or iPad to open Gaia: