SharePoint 2013 - 'Sorry, Apps are turned off' error

You configure the App Management Service in the farm but while trying to add any app you receive the following error
Sorry, apps are turned off. If you know who runs the server, tell them to enable apps.

Cause

The server was running out of memory. 

Resolution

1. We tried to add an app using a non-system account, however we received the following error:

Sorry, apps are turned off. If you know who runs the server, tell them to enable apps.


2. We tried to browse SharePoint Central Admin - Apps - Configure App URL's and got below error: Sorry, something went wrong Settings or services required to complete this request are not currently available. Try this operation again later. If the problem persists, contact your administrator.
   Technical Details
   
   Troubleshoot issues with Microsoft SharePoint Foundation.
   Correlation ID: 6379209c-5068-40f4-5407-6ef37b5fe7a3
   Date and Time: [Date and Time]
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   Go back to site
3. Tried to browse to http://localhost:32843/3149c16fb70b4ced8e10c0c28e334a3d/subscriptionsettings.svc and http://localhost:32843/97d4210c929e443a9c69e8cd49012a51/AppMng.svc but got the below error: Server Error in '/3149c16fb70b4ced8e10c0c28e334a3d' Application.
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   Memory gates checking failed because the free memory (144322560 bytes) 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.
   Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
   Exception Details: System.InsufficientMemoryException: Memory gates checking failed because the free memory (144322560 bytes) 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.
   Source Error:
   An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
   Stack Trace:
   [InsufficientMemoryException: Memory gates checking failed because the free memory (144322560 bytes) 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.]
   System.ServiceModel.Activation.ServiceMemoryGates.Check(Int32 minFreeMemoryPercentage, Boolean throwOnLowMemory, UInt64& availableMemoryBytes) +121924
   System.ServiceModel.HostingManager.CheckMemoryCloseIdleServices(EventTraceActivity eventTraceActivity) +86
   System.ServiceModel.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity) +883
   [ServiceActivationException: The service '/3149c16fb70b4ced8e10c0c28e334a3d/subscriptionsettings.svc' cannot be activated due to an exception during compilation. The exception message is: Memory gates checking failed because the free memory (144322560 bytes) 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..]
   System.Runtime.AsyncResult.End(IAsyncResult result) +650220
   System.ServiceModel.Activation.HostedHttpRequestAsyncResult.End(IAsyncResult result) +210733
   System.Web.AsyncEventExecutionStep.OnAsyncEventCompletion(IAsyncResult ar) +166
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   Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18044
4. Opened Task Manager and found the server was consuming complete memory on the box.
5. We can follow below steps to resolve the issue:
a. Perform IISRESET so that it will release the memory. This is only a short-term solution
b. Increase memory on the SharePoint servers as a long-term solution