Quell is a peaceful puzzle game in which kids slide a droplet of water around a board to collect pearls and advance through a series of levels.
Compared to other popular puzzle apps such as Doodle Jump and Toy Balls, this one actually seems to lower blood pressure instead of raising it.
Why we like it:
Early levels are easy to solve, but then things get interesting. Kids have to think really hard to keep advancing, and to tackle traps, hazards, and conundrums along the way.
When they get stuck — and they will — they can spend coins (which they earn by completing levels) on hints or solutions.
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We tested the Android version of Quell on the Kindle Fire. It’s also available for the iPhone and iPad, and requires iOS 3.1.3 or later. Developer: Fallen Tree Games. Read our disclosure policy.