I think it is my duty to leave this reference so that freetour.com and future travelers be aware that this so called walking tour is fake and non-existent.
We booked this walking tour for 2 people, myself and another passenger who had a stopover in Addis Ababa and were offered accommodation at Ethiopian Airlines' Skylight Hotel. It seemed like a legit and great offer as the walking tour's meeting point claimed to be at the same hotel, and we got booking confirmation etc... It turned out not to be the case, there was no tour, even the meeting point indicated on the map was a random pin on the hotel property that had no actual access.
We left a message to the guide at the freetour.com and only got response a few hours later asking to contact the guide via WhatsApp, which we didn't bother to do as we were already on our way to explore the city ourselves.
So maybe a tip for readers of this review: the city is not as dangerous as people advertise it to be, local people are nice and friendly, but it might be a totally different world and it is always advised to take cautions. Also the hotel is far from the center where key attractions are, so walking is not really a good choice to start with. You could use the Uber-like app named RIDE to get to the center and back and perhaps explore the center on foot. I wish you good luck in finding a legit walking tour with a legit local guide, but if not, you could totally do it yourself!