SharePoint Memory gates checking failed because the free memory is less than 5% of total memory. As a result, the service will not be available for incoming requests. To resolve this, either reduce the load on the machine or adjust the value of minFreeMemoryPercentageToActivateService on the serviceHostingEnvironment config element

This is the one of the strange issue you will find when you deploy your SharePoint App to app domain.

This issue will occur because of the memory issue most of it will be consumed by the SharePoint.

Here is the solution :

Open Services wizard :

Go to Start -> type Services.msc

This will launch the services windows there you can find the service with name Sharepoint search host controller

Just right click on and Restart ( It will taken around 4-5 mins time ). But it will release all the leaked memory and consumed memory. You can verify the same in memory section from you windows manager just for your verification.

Then ReDeploy your solution this time it will sure go on successfully.