(10) Utilities & Productivity:

FlickType, proper keyboard

FlickType Notes for note-taking

WatchChat for WhatsApp (Supports FlickType)

Battery Watcher, to check your phone's battery percentage from your watch

Coyomi, proper calendar app

‘Complicate It’ for custom text in complications (Watch face widgets)

Countdowns

Shazam, for identifying music

Wunderfind, alert you when your phone is out of range

Remote, lets you control your Mac from your watch (and phone) - much better than TeamViewer in certain ways

(3) Social Media Apps:

Chrip for Twitter

WristWeb for Facebook

Lens for Instagram

(12) For better health stats:

Fitness Friend

Heart Analyser

HeartWatch

CardioBot

Cardiogram

Activity Stats

ActivityTracker

Pacer

Steps

StepsApp

Pedometer++

MyFitnessPal