OneNote Windows 8 and RT versions have this week received a new
update from Microsoft which has brought with it a handy new drawing
feature.
The new OneNote Windows 8 and RT has added the ability to finger
paint on the screen of your device, however inking with a pen still
remains the preferred experience if you own a Surface Pro ands can
easily be switched between pen and touch. 
With the new OneNote Windows 8 and RT update a new navigation has
been added to make it easy to choose pen colours, customise your
thickness, and store these combinations as a ‘favourite’ pen , when
required. Microsoft explains:
"Many of our users expressed the need to be able to draw on the
touch devices that do not ship with a pen. With this update to OneNote
for Windows Store, now you can draw with your finger!”-”To download the
OneNote Windows 8 and RT update, simply tap on the Store tile in Windows
8, and then tap or click Updates at the top right. If you haven’t
installed the OneNote app from the Windows Store”
You new OneNote Windows 8 and RT update is now available to download from the Windows Store for free.
Source: OneNote | 