Due to crossover from both apps' architecture using OpenHome/UPnP, the Linn app does have a limited ability to control Auralics., but they are two different apps.
It is too bad that the Linn app doesn't have more functionality with Auralic devices. Since Auralic left the US market, they have removed the DS Lightning download. This means anyone wanting to buy on the secondary market has no way to control the device, unless they already have the app from a previous Auralic purchase.