Those are mostly app updates then features. The other half are some things that look cool on WWDC keynote slide, but in practice rarely one notice it's even there. Siri Proactive ? I'm cracking up.iOS 9 has a lack of new features?
- Proactive Siri/Proactive apps on lock screen
- Content aware Siri ("remind me of this")
- Deep Search
- Low Power Mode
- Much improved Notes
- Improved email attachments
- Transit for Maps app
- iCloud Drive app
- Auto Discovering/Adding events from emails
- Depending on the carrier iOS 9 has brought wifi calling
- Wifi Assist
- Metal OS wide
- 3D Touch
- Live Photos
- Split Screen
- Slide Over
- PiP
- Safari Content Blockers
- News app
- App Thinning/Slicing
- Much Smaller overall iOS install/download size
- The ability to temporarily delete apps to make space for installing iOS and then re-installs the apps back
- Night Shift
- iCloud for iBooks
- Password/Touch ID protection for Notes (which can and probably will get expanded into more apps in iOS 10 and beyond)
- Multi User Education/Classroom app (which multi user can and probably will get expanded to iOS wide for iPads iOS 10 and beyond)
I'm probably even forgetting some, but that's a pretty extensive list of features iOS 9 has brought to us so far.
Also LOLd at "Metal OS wide" as a feature.