Looking for an iPad Whiteboard

Curious if anyone has any recommendations for an app to use on iPad for mocking up UI prototypes, diagrams, and general whiteboard drawings.

I’m mainly looking for the whiteboard aspect, not a full UI/UX flowchart, but simpler for quick and dirty napkin drawings.

Would be beneficial if we could share drawings easily to JIRA or Google Drive

Looking for iPad/tablet solution so we can have design meeting away from our desks.

Questions: * What is your drawing app recommendation? * What is your stylus recommendation? * Anything else useful??