The 26-year old joined the Grecians in August 2013 and last season scored 21 goals in 46 appearances.
Exeter City manager Paul Tisdale said he was proud of the progress David had made during his time at the club and wished him all the best for the future.
It's not known how much the Championship side have paid.
Storm Chandra causes disruption across Devon
School closures and travel chaos across county
Devon demands government cash for storm repairs
Calls for more flood defence
Two arrested after body found in Plymouth waters
Teenagers questioned on suspicion of murder
Theatre raises over £50K for youth programmes
Festive appeal total doubles
Clear-up begins after Storm Ingrid
Strong winds and rain batter Devon
Car park hike at beauty spot will impact residents
Council slammed for penalising locals
