Hewitt has recently been released by Sky Bet Championship side Burnley after having his contract cancelled by mutual consent.
The former Burnley scholar, 22, made two first-team appearances from the bench, in April 2012 and December 2013, while his solitary start for the club came in the Capital One Cup in August 2012.
Hewitt enjoyed two loan spells while at Turf Moor, spending three months at Alfreton Town in 2013 before spending the remaining month of the 2014/15 season at Southport.