Some interesting ones:
- Screen recording/capture
- Battery status
- Barcode Detection
- Bluetooth
- Sensors (e.g. Accelerometer)
- Wake/screen lock
- Color picker
- Vibration
- MIDI
- USB
- Contacts picker
- Presentation (AirPlay, Chromecast)
- Virtual reality
I'm amazed at how quickly I can throw together a front end feature in JavaScript on my otherwise html site.
Really all of web impressed me over the desktop/app counterparts. I wrote and read to/from a php database with less than 2 hours of time. Laravel has me doing user authentication + useful coding in less than 40 hours after the tutorial.
No permissions required.
I had issues as recent as last year's new products.
But otherwise I love the concept of hardware access with HTML. The embedded guy in me thinks the future is going to be crazy. I can't quite wrap my head around the possibilities.
I also keep Bluetooth disabled on my mobile devices. It's used extensively to ID and track people and their devices. For things that don't move and are only ever paired to a single thing (like a speaker) it works fine. Most of the complaints I hear about bluetooth are from people who pair multiple devices to a single source and want to easily switch between them.