Rulerless is a mobile application system that contributes to early recovery and reconstruction from flood damage caused by heavy rains and floods. In the past, damage assessment required dispatching personnel to the site, which made damage assessment time-consuming. This application enables measurement of damage conditions, etc., necessary for damage certification, using only a smartphone, leading to prompt support for disaster victims. In addition, operational efficiency can be improved by using this for equipment inspection and equipment delivery/installation simulations.