If you are using MobileFamilyTree (Apple App Store), you are obviously using MacFamilyTree 5.7 or MacFamilyTree 6, which are Mac OS X genealogy programs from Synium Software.
MobileFamilyTree synchronizes its genealogy data with MacFamilyTree – without MacFamilyTree, MobileFamilyTree is useless.
Synium has released a new version of MacFamilyTree, MacFamilyTree 6.0.5 (MacGenealogy.org), that contains fixes for MobileFamilyTree synchronization issues and it is highly recommended if you are using the version 6.0 line of MacFamilyTree.
You can auto-update or download the latest version of MacFamilyTree at Synium Software.