Arduino library to interface through I²C with the NXP NTAG (NT3H1101 and NT3H1201). These are fully ISO/IEC 14443 A and NFC Forum Type 2 Tag compliant.
Attention: The herein used NDEF-library (which I didn't write) currently eats up too much stack space for arduinos with 8bit AVR MCU and is therefore not usable.
Altium Designer has been used to create a tag PCB with a Class 6 type antenna.
The NXP-website has a lot of useful resources for the NTAG-family of NFC-tags.
For new designs, the NT3H2111 might be a better option. It's cheaper, offers more functionality and should be compatible with the NT3H1101.
Either use an NFC-enabled phone or use an RFID-reader module with a PN532. Code for the PN532 reader module can be found here.