Grimsby sign Cambridge United's Nathan Arnold while Scott Brown, Craig Clay and Shaun Pearson sign new contracts.
Conference champions Barnet sign experienced striker Kevin Lisbie following his exit from Leyton Orient.
Conference club Welling sign former AFC Wimbledon midfielder Ricky Wellard following his exit from Sutton United.
Kidderminster Harriers midfielder Jack Byrne leaves the Conference club after rejecting the offer of a new contract.
Hull boss Steve Bruce has called on the club to resist offers for James Chester, Robbie Brady and Ahmed Elmohamady this summer.
League Two club Accrington Stanley sign defender Matty Pearson from Conference side FC Halifax Town on a one-year contract.
Relegated Tranmere sign Halifax midfielder Lois Maynard and former Fleetwood defender Liam Hogan.
Grimsby Town defender Josh Gowling and midfielder Jack Mackreth sign new deals with the Conference side.