@coloco GNU Social doesn't have an API to get a list of ”favorites of me”. But there is a workaround for this: even now in AndStatus you can create an automatically syncable Search timeline with ”myusername” as a search word. Thus you will be aware of any mentioning of you, including well known ”someuser favorited something by myusername...” messages.
E.g. I have syncable "Search 'andstatus' combined" timeline (i.e. automatic search in several GNU Social instances) and I even made that combined timeline the Default one. This is why I always have up-to-date list of any AndStatus-related messages. In all Social networks, including Twitter, which support Search feature. See attached screenshot of my "Manage Timelines” table. https://loadaverage.org/attachment/3201676