As a public transport company, or by contacting them:
Display at stations (possibility to use the CityTourPlayer poster generator)
Posting in the kiosks
Display in vehicles
Display on applications/websites
Include the tour QR code in your route brochures.
Create stickers with the QR code and stick them at the stations (this takes less space than a full poster).
Social networks
As a tourist office or as a city or by contacting them:
Display at your city's kiosks
Insertion of the QR Code in your city's tourist brochures
Creation of roll-ups presenting your AudioGuide
Communication to hotels and restaurants as well as tourist attractions in your city with posters, brochures, or leaflets describing your audio guide. In addition, hotels often like to be able to offer various tourist activities, especially if they are free.
As a private person:
Consider presenting your project to your city, tourist office, and public transport, they might be interested in helping you to promote your project. Explain to them that it enhances their line. For this purpose, do not hesitate to consult our brochure!
Contacting restaurants, hotels, museums, etc., and offering them, with or without a contribution, to be included in the AudioGuide. This can be a great way of advertising their establishment.
Online forums and other sites with good tourist tips for the region
In any case, a long-term communication plan seems more interesting, as this is an activity that is primarily aimed at tourists in your region, and which will therefore be discovered mainly in tourist brochures, on the Internet, and by word of mouth.
You should also think about communicating in several languages if your audio guide offers several.
Finally, if you do not wish to make posters at the stations, it is still possible to make small stickers with the QR code and with only AudioGuide (+logo CityTourPlayer +your logo if desired) on them which you can then propose in a brochure, flyer or other. With the prior agreement of the public transport company, you can also stick them on the stops and thus free up display space, but above all, you allow anyone who has heard about your project not to be lost when arriving at the station.