Most period apps are built for women. HerBattery is built for the man who wants to understand her. A battery on your homescreen shows exactly where she is in her cycle — her energy, her mood, her desire. 7 phases, color-coded, always one glance away. 100% offline. No account. No cloud. Your data never leaves the phone. 32 languages. Less than a coffee a year (€9.99), with a 7-day free trial — no credit card needed. She's not random. You just didn't have the data.