The word ringleader 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: 15
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (52 words)
aligned, aligner, angered, angrier, dangler, darling, dealign, dealing, deleing, deraign, derange, dernier, drainer, earlier, earring, enlarge, enraged, general, gleaned, gleaner, gnarled, gnarler, gnarred, grained, grainer, grander, grenade, grinder, lagered, lardier, larding, leading, learing, learned, learner, leering, lineage, nerdier, randier, rangier, readier, reading, realign, rearing, redline, reeling, regrade, regrind, reigned, reigner, relearn, relined