"The type or namespace name 'App' could not be found" Xamarin Forms

If you're still having issues check to see that the PCL project is referenced under the references in the solution explore the refrences option in the solution explore

• Right click on the references option and click add reference.
• in the dialogue box, select the PCL project and click okay.

this should solve the error

In my case, I found there is a bug with Visual Studio 2017 when making a cross platform Xamarin Form app with the generated code if there is a dash in the filename.

It looks like it tries to snake case the title and then complains about not finding that file.

For example, for "my-project", it starts looking for "my_project" in some areas of the generated code.

Using a project name with no symbols seems to solve the issue.