Not only steps, StepsApp counts also floors!

You get floors/flights of stairs with a simple tap on the big circle – to return to your steps count, tap again on the circle.

StepsApp only ascending stairs.The floors / flights of stairs displayed in StepsApp are the same as displayed in Apple Health. One floor/flight of stairs is counted as about 10 feet (3 meters) of elevation gain. That’s approximately 16 steps.

Please check the following settings:

• Open Settings on your iPhone
• Go to "Privacy"
• Tap on "Health"
• Tap on “StepsApp”
• Enable "Flights Climbed