The word subroutines is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 17
Highest Scoring Words With Friends™ Plays In The Letters
Seven Letter Word Alert: (66 words)
besorts, bistros, boniest, bonuses, bossier, bousier, bruises, burnout, busiest, busters, bustier, estrous, inserts, insures, nitrous, norites, nosiest, nutsier, obtuser, oestrus, orients, ousters, outburn, outruns, resnubs, riboses, rosiest, routine, rubouts, ruinous, seniors, serious, sinters, sinuous, sorbets, sorbite, sorties, sourest, stoners, stonier, stories, stourie, strobes, suberin, subnets, subnote, subsite, subsort, subtone, subunit, suiters, suitors, sunrise, sutures, tensors, tenuous, tonsure, toruses, tribune, triones, turbine, unburst, uniters, unrests, unrobes, unsorts