Um. The HTC One MIGHT be similar, since its similar screen size i think BUT its not flat on the back, its actually curved.
so the HTC First is UNIQUE yey haha. I got my awsome case for like 2 bucks off cellphoneshop.net
its clear and 2 piece and doesnt come off when the phone is dropped and it is quite thick so it protects the phone really really well.
Motorola Atrix HD - White - Cyanogenmod 11
HTC First - White - AOSP 4.1.2 Rooted
HTC One (M7) - Silver - Cyanogenmod 11
ZTE Avail - AOSP 2.3.7
LG Thrive - Cyanogenmod 10.2