I don't like the iPhone, but at least they keep their naming conventions very straight forward.

iPhone (1)
iPhone 3g
iPhone 3gs
iPhone 4
iPhone 4s
etc.

Hopefully Jolla keep it simple and just call the next Jolla, the Jolla 2.

Some examples of awful naming conventions. The HTC One has to have the worst, these are all actually unique devices!

HTC One V
HTC One SV
HTC One S
HTC One X
HTC One XL
HTC One +
HTC One
HTC One X+
HTC One Mini
HTC One Max
HTC One (M)
etc.

No wonder HTC sales plummeted - no one had a clue what was the name of the phone they were supposed to be buying!

Another naming convention that was awful was Symbian.

Symbian^3/Anna/Belle
Symbian^2[45]
Symbian^1/Series 60 5th Edition
Series 60 3rd Edition

Ugh, how do you even pronounce a ^ character? Just keep OS names simple and use the standard major/minor version of numbers!