Good but 2 big suggestions.

I like it but a little confusing. Suggestions: a pause button rather than double tap. I tend to pause a lot by accident. Also, a "solve" button would be interesting. Often I solve the puzzle by accident. Id rather have the option to solve the puzzle by placing things and then clicking on "solve" to see if I have it right. Solving it by accident is not fun and takes away greatly from the good challenges youve created. Maybe this "solve" button could be optional.

Luckeydogs about Taijitu: A Game About Balance, v1.0.3