The word viewfinders 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: 23
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (43 words)
defiers, definer, defines, deifier, deifies, deniers, derives, deveins, deviser, dewires, diverse, diviner, divines, drivein, edifier, edifies, endives, enviers, fenders, finders, friends, insider, inverse, newsier, refinds, refined, refines, reified, reifies, reviews, revised, rewinds, sinewed, swerved, veinier, versine, viewers, weiners, widener, wieners, wienies, winders, windier