Southend have signed striker David Mooney on a free transfer from Leyton Orient.
Swindon have signed former Arsenal academy defender Brandon Ormonde-Ottewill on a two-year contract.
Scunthorpe have made their eighth summer signing after the arrival of forward Luke Williams from Middlesbrough.
Southend midfielder Michael Timlin has signed a new two-year contract with the club.
Walsall have signed goalkeeper Neil Etheridge from Charlton on a two-year deal.