It only requires portfolio read access with an API key generated by your account on HavelockInvestments.com, it cannot perform any other actions on your account.
I'm in the process of adding more functionality, including charts. I also have a small group of beta testers on Google Play providing feedback on new features. If you're interested in joining the beta testers, join the myHavelock Google+ Group then click the "myHavelock Early Access Enrollment on Google Play" on the group page.
Right now I'm doing this solely for donations: 1JXgV2fAGyMRfNoLH5U6LL4xLCbXBWn3fF