OnePlus One Recovery Mode
- With the device powered down, hold the Volume Down and Power buttons.
OnePlus One Fastboot Mode
- With the device powered down, hold the Volume Up and Power buttons.
OnePlus One Developer Mode
- Switch it on going into the Settings Menu
- Scroll all the way to "About Phone"
- Tap the "Build Number" 7 times
- Once unlocked you will see a new "Developers Options" menu within settings