ownCloud is a free and opensource file sync and share app which is self hosted.

CloudBuckit is a desktop application that connects all of your cloud storages and FTP servers in one place.

Pushbullet is a service that acts as a bridge between your mobile and desktop OSes, sets the gold standard for developer updates.

Join allows you to easily do stuff remotely on your Android and PC devices like SMS, notifications, clipboard, and much more.