Montessorium: Intro to Words

Well-crafted app helps emerging readers and writers build words
Bottom Line: This app will work best for students who already know their letters and can then work on word building, word play, and letter-sound recognition.
Word Wagon - by Duck Duck Moose

Charming objects and animals turn spelling into play
Bottom Line: Word Wagon is fun to use with students at various spelling skill levels.
Avokiddo ABC Ride

Inventive letter-learning activities take kids on a near-perfect ride
Bottom Line: A fun way for kids to play thoughtful games and explore letters and words. A few small changes could really beef up letter learning.
Sight Words - An early reading & spelling adventure!

Repeatedly identify, spell sight words in fun, semi-customizable games
Bottom Line: A variety of kid-friendly activities gives students lots of exposure to and practice with commonly used sight words.
Word Wizard for Kids

Super-structured spelling support and word-building free play, too
Bottom Line: Helps kids improve spelling through pre-made or custom lists and word building.
Tiggly Doctor: Spell Verbs and Perform Actions Like a Real Doctor

Practice spelling while practicing medicine
Bottom Line: G-R-O-S-S spelling fun brings shock value to spelling and vocab.
Spelling Shed

Drill-based practice caters well to teachers, less so to kids
Bottom Line: When teachers use the whole program, including the offline materials like printables, there's potential here for a comprehensive if traditional approach to spelling drills.
Mystery Word Town Spelling

Old West crime-fighting takes kids on a spelling adventure
Bottom Line: A challenging and really fun way for kids to practice spelling.
SpellBoard

Well-designed, kid-empowering spelling list creator
Bottom Line: It's a quality app but needs some oversight; it would be nice if you could track multiple students' scores at once.
Osmo Words

Versatile word game challenges across content areas and abilities
Bottom Line: Fun game-like way to review spelling or content vocabulary.
Scribblenauts Remix

Vocab-building word puzzles inspire creative problem-solving
Bottom Line: Wide-open problem solving builds creativity, vocabulary, and spelling skills, but controls can be tricky.