Using the Windows 8 library
Requirements
Visual Studio 2012 (Update 1 or later)
NuGet (latest version)
Install the BugSense NuGet package using the Package Manager Console:
PM> Install-Package BugSense.W8
You can also use the Package Management Dialog in Visual Studio to install the 'BugSense.W8' package.

Installing BugSense via NuGet in Visual Studio 2012
Alternatively you can download the BugSense-W8-v3.4.zip (Release Notes) file & add a reference to BugSense-W8.dll in your Windows Phone Project.
Then, all you need to do is go inside you App.xaml.cs file and add the code below inside the constructor. Don't forget to use your Project API key that you'll find in your dashboard!
If you are in debugging mode (ex. Step-by-Step) BugSense Handler will recognize that and will not send the exception. This happens because when you are debugging your app, Visual Studio does a great job of letting you know where the error is.

One line installation in App.xaml.cs
Now you can ship your application and stay cool. We will make sure you won't miss a bug.
End user communication
When an error occurs the user is informed by a slick Popup. This option is customizable. You can:
Display a Fix Notification when a user experiences an error that is been fixed in new versions of the app
Display nothing and just keep the application running.
Display a popup with customizable Title and Body.
Display a confirmation popup with customizable Title and Body allowing the user to decide if he wants to send the error report. An example screenshot is displayed below:
Advanced Options
You can also use BugSense to log handled exceptions and send useful custom data
Monitor if async Tasks have been completed successfully
Add Breadcrumbs and cutom data to crash reports
Set a method to be executed before the app crashes (ex. save state)
Use BugSense along with the VisualStudio debugger
Track an event
Set (override) a localized fix notification
Using the Javascript library
landing.docs.html5.p1 bugsense-3.4.js (Release Notes) file and store in it along with you other Javascript files. Alternatively you can use the BugSense hosted version (see the following Gist).
Then all you have to do is to include the script in the default.html page and page initialize it.
Add bugsense.js to your project
You must enable the Internet capability.
Stacktrace is available only for handled exceptions due to WinJS implementation. In this case the url, line and line number will be extracted from the stacktrace.
Bugsense.js uses CORS to send crash reports.
If there is no Internet Connection the report will be stored and sent next time the app is launched.
If there is no Internet Connection the report will be stored and sent next time the app is launched.
When an error occurs the user is informed by a slick Popup. This option is customizable. You can:
Display nothing and just keep the application running.
Display a popup with customizable body.
Display a Fix Notification when a user experiences an error that is been fixed in new versions of the app
landing.docs.html5.h3_2
Bugsense.js allows you to register handled exception as well and append metadata to the crash report.
Metadata & Breadcrumbs
You can add custom data to the BugSense crash reports as well as breacrumbs to help you debug your app faster!