Android
To check to see if your android phone is NFC compatible you can check using NFC World
NXP Apps
NFC TagInfo by NXP – Play Store
NFC TagWriter by NXP – Play Store

NFC Tools has a pro and a Free Version. If you download and use the free version you’ll understand that the app covers many features and the pro is definitely worth getting.
NFC Tools
NFC Tools Pro – Play Store
NFC Tools – Play Store


Other Android Apps
NFC Tasks – Play Store MIFARE Classic Tool – MCT – Play Store
IOS (Iphone)
Currently IOS lacks write support for NFC. However they’re a few NFC tag info tools that can read the implants and other NFC tags.
NXP App
Taginfo NXP – AppleStore

Can see a video of it here in on a xNT.
Other IOS Apps
NFC Reader for Iphone – AppleStore
GoToTags –AppleStore
NFC Ideas – AppleStore
Windows
Windows has a limited amount of applications available for Reading/Writing tags currently.
GoToTags
Download from manufacturers – website

NFC Tools
NFC Tools (Same company as the android app)
Download from manufacturers – website

OSX (MacOS)
More and more applications are being released for MacOS, Here are the top few.
NFC Tools
NFC Tools (Same company as the android app)
Download from manufacturers – website Mac Appstore

Can see it in use here
Other OSX Apps
NFC Ideas (Same as the IOS App) – AppleStore