Dundee sign midfielder Lewis Spence on a one-year deal and extend defender Kostadin Gadzhalov's stay for another year.
Queen of the South say they held off competition from clubs in England and Scotland to sign Dumbarton goalkeeper Alan Martin.
The former Rangers midfielder has landed a new club, five years after quitting Ibrox for Sheffield Wednesday.
Nicky Clark's injury-time winner sees Dunfermline beat Queen of the South to confirm fifth place in the Championship.
Dunfermline end their home campaign on a high with a 3-1 win over play-off bound Morton.