When a relationship breaks down, so too can communication. But if you have kids together there's still lots of conversations that need to be had: custody arrangements, kids' medical appointments, scheduling school events, and sharing school reports, are just the start of the list.

That takes a commitment to communicating well, but if you're separated, that can come with a layer of frustration or even anxiety.

Some parents are using co-parenting apps, to try to get this stuff right for their kids' sake. How useful are those tools?