The word demandingly 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: (31 words)
addling, aligned, annelid, damning, dandily, dangled, dealign, dealing, denying, eddying, geminal, gladden, gmelina, inanely, landing, leading, leaning, lending, lineman, madding, mangily, mangled, meaning, melanin, melding, mending, midland, mingled, yealing, yeaning, yelming