I've never bred corns, but I use Microsoft Excel spreadsheets for my balloon molly breeding. Right now I've got approx. 4-7+ lines going.*
:-offtopic
*chocolate dalmations, green dalmations (& greens), lyre-tail dalmations (& non-lyre-tail dalmations), lyre-tail calicos (& non-lyre-tail calicos). Also working on a trend for late-blooming males, as those develop a better body shape.
Just had a birthing this morning of what I'm hoping will be lyre-tail calicos.