You can request support for mulitFEED by tapping the "eMail Support" button on the front page context menu and on the overflow action menu on the Embedded, QuickView, FeedFinder, and Global Settings pages. If you have a keyboard device such as the Q10 or Q5 you can also send a support request by pressing Alt+E on any of those pages, plus the Feed/Subfeed Settings pages. This is the preferred method since a it pre-populates the eMail with the OS version, app version, upgraded level, and device type to aid arsMOBILIS with the diagnosis, but you can also just send an eMail to:
NOTICE: Do NOT post a support request in a review on BlackBerry World. There is no way for developers to respond to reviews in any way, and also no way to identify you and respond via other channels such as eMail.