The word mackintoshes 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: 25
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (99 words)
achiest, aconite, actions, aitches, amnesic, animose, anthems, ascents, ascites, ashiest, atheism, atomics, atomise, atonics, caisson, cakiest, caseins, casinos, caskets, cations, catkins, cession, chaises, chamois, chaoses, chasten, chemist, cinemas, consist, cosiest, cosines, ethnics, haemins, hankies, hastens, histone, homiest, hotcake, hotness, icemans, icemass, incests, incomes, inmates, inseams, insects, intakes, ketosis, kinases, kitchen, machine, mascots, masonic, matches, messiah, miscast, misseat, mistake, mitoses, moisten, monkish, mosaics, nematic, nickase, nosiest, notches, notices, octanes, oecists, sachets, scathes, schemas, schtiks, seamost, seasick, secants, section, seitans, sestina, shitake, shticks, sickens, sickest, sitcoms, skaiths, smokies, snakish, sockets, somatic, somites, stamens, stances, stomach, stomies, stonish, theisms, thicken, thiones, tocsins