Sprinkle both sides of steak with chili powder and 1/4 teaspoon salt. Heat oil in a medium skillet over medium-high heat. Add the steaks and cook, turning once, 1 to 2 minutes per side for medium-rare. Transfer the steaks to a plate, cover with foil and let rest while you make the salsa.
Add tomatoes, lime juice and the remaining 1/4 teaspoon salt to the pan and cook, stirring often, until the tomatoes soften, about 3 minutes. Remove from heat, stir in cilantro and any accumulated juices from the steaks. Serve the steaks topped with the salsa.