Re: dev options
These are the instructions for a Motorola and Nexus:
-Touch Settings
-Touch About phone
-Touch the Build number field 7 times
Worth a try.
Actually it is the same for all Android-smartphones, you just need to know where is the build-info. located
For the One M8
1) Settings
2) About
3) Software information
4) More
5) Build number
Just repeatedly tap the build number until a message appears for you saying that you are now a developer.
Once you get that message, go back to the main Settings page, and you will see the Developer options above About.
Sent from my HTC One M8