I'm playing Diversion for android and have compiled a full list of the double-point character that works for each level. The way they work is simple: you just choose the indicated character before playing the associated level and you'll earn double the gems/points at the end.

I'd personally suggest that you compile your own list by keeping your eye out for the blue "character" disc floating somewhere down-low in the level (very often right before the end) and figure out how to get your character to fall into it. When you do that, the level-failure screen will mention what character gives you double-points for the level you're on. You can then use this list to fill in any that you are having trouble with. Most of them are pretty easy, but sometimes the disc will be in a different spot on each restart of the level and/or may be hard to see. Only a few are a bit problematical to coerce the character to fall into, with most being as easy as falling off of a log.

If you're just starting out, I'd recommend that you just enjoy the game for a while without obsessing over double points, or even being overly hung up on getting all 3 stars. Once you've gotten the hang of things, its nice to come back later (which you have more characters) and do the levels again with an eye to maxing out the points.

You may also be interested in some ezonecom walkthrough videos, some walkthrough videos by Michael Rigoni, and a text walkthrough for the various levels.

If you have corrections/additions/etc., feel free to .

Each of the Endless Bonus levels (above) are unlocked when you get a certain character:

The following codes can be typed on the reedem page for fun and profit:

Here are all the characters that I know about: