Near-field communication (NFC). It came out in 2010 for Android and Microsoft phones, but has been hamstrung by Apple for most of its development. I had severa

Near-field communication (NFC). It came out in 2010 for Android and Microsoft phones, but has been hamstrung by Apple for most of its development. I had several startup ideas which required NFC market penetration on phones, but which even today are impractical due to Apple's chokehold on NFC APIs for fear of a payments competitor. In order to even find "tap to pair" devices, you often need to seek out the one manufacturer or option available. There should be personal phone-to-phone "tap to pay" by e-cash or cryptocurrency. "Tap to auth" using your phone. "Tap to key exchange" should be part of doing business, sending "business card" contact details as well. Samsung had S-Beam, "tap to share files" securely with WiFI Direct. But even with the addition of Core NFC, you need to find a responsible adult with an Android phone to even write a single bit as an iPhone owner.