An apparatus for indicating an ice fishing tip-up strike or mark trails in low light conditions by a flashing light source located on extreme end of apparatus includes a tilt switch to determine whether flag arm is in horizontal or vertical position. A reflective enclosure of the tilt switch/flashing light source is used to protect the electrical connections of conductors, tilt switch and flashing light source. Conductors connect the power source via a jack/socket junction to apply and disconnect power from the flashing light source. The apparatus is attached to a flag arm of existing known fishing devices.