OneNote for Windows 10 Mobile devices just got updated for Windows 10 devices to v17.6131.10032. This update added full screen drawing mode and more.
• Added a full screen drawing mode to maximize screen real estate and eliminate distractions
• Added proofing tools for correcting or ignoring misspelled words
• Additional bug fixes and polish
Recent updates also included:
• Ability to insert a photo from the camera
• Ability to change ink thickness
• Reduced the appearance of the keyboard when inking
• Addressed problems some users had opening OneNote
• Full drawing capabilities when your Surface is locked, including ink color, highlighter, eraser types, and more
• Ability to change the font and font size
• Resolved sign-in issues that prevented some users from opening OneNote
Update it from Windows Store.