The word webmasters 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: 19
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (24 words)
basters, beaters, beermat, berates, besmear, bestrew, beswarm, breasts, embases, masters, rebases, rebates, remates, reseats, restems, reteams, seamers, seaters, steamer, streams, sweater, teasers, warmest, wasters