Texting About Schedules is Getting Ridiculous

My ex and I argue about literally everything via text. I asked about switching one week because of a work thing and it turned into a whole thing about how I don't respect the schedule we agreed to. Meanwhile she's the one who changes it constantly. Looking into using one of those co-parenting apps. Heard good things about OurFamilyWizard. Does anyone use that? Trying to keep things focused on the kids and off emotion.