Has.AlTaiar 

This library is to simplify the connectivity status check on Android and iOS by providing a unified simple to use API to detect connectivity on both platforms. This package is compatible with the following .net platforms: Xamarin.iOS (Unified), Xamarin.Android, and soon (Windows Phone... More information

A unified, simple to use library that enables developers storing, accessing, updating and deleting keys and passwords on multiple platforms. Internally, the library uses iOS KeyChain and Android KeyStore features. The library exposes KeyChainHelper which is a simple one-entry to the library on all... More information

An easy to use extension for SQLite.Net PCL that allows you to seamlessly encrypt/decrypt data when inserted/accessed from the database by adding one simple attribute. Works great one all major platforms (iOS, Android, Windows Universal)