The word voltmeters 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: 18
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (26 words)
emoters, letters, melters, meteors, mettles, mottler, mottles, omelets, overset, remelts, remotes, removes, resmelt, resolve, revolts, revotes, roselet, rosette, servlet, settler, smelter, svelter, teleost, telomer, trestle, vetoers