I'm a sucker for code names. They're so Bond. While Apple doesn't use public code names for iOS the way the company does for OS X — no big cats like Snow Leopard or California landmarks like El Capitan — it does use internal code names primarily based on ski resorts. They're not meant for the public but, once a version of iOS goes public, they're not hard to find.

1.0: Alpine / Heavenly

1.1: Snowbird

2.0: Big Bear

2.1: Sugarbowl

2.2: Timberline

3.0: Kirkwood

3.1: Northstar

3.2: Wildcat (iPad only)

4.0: Apex

4.1: Baker

4.2: Jasper (4.2.5 - 4.2.10: Phoenix)

4.3: Durango

5.0: Telluride

5.1: Hoodoo

6.0: Sundance

6.1: Brighton

7.0: Innsbruck

7.1: Sochi

8.0: Okemo

8.1: OkemoTaos

8.2: OkemoZurs

8.3: Stowe

8.4: Copper

9.0: Monarch

9.1: Boulder

9.2: Castlerock

9.3: Eagle

10.0: Whitetail

10.1: Butler

10.2: Corry

10.3: Erie

11.0: Tigris

11.1: Bursa

11.2: Cinar

11.3: Emet

11.4: Fatsa

12.0: Hope

13.0: Yukon

While knowing these names doesn't add to the feature set of the software, it does add a little depth to the experience. And because they're technically secret code names, they're ever so much cooler than desserts.