[Recommended] Least Six Services

Add at least six services/features you are interested in implementing. Include the following in each suggestion you post:

At the top, include a descriptive and well-formatted title.

A description of the service or feature, and why it interests you.

One link to the primary resource describing the service/feature (official sources only).

One link to a secondary resource that describes how to implement the service/feature in Xamarin.Forms.

The body of your posting must be a minimum of 25 words in length