Build a web service. Long term partnership possibility

Hello We are international consulting agency and we're looking for a new outsourcing partner. Currently we're working on the project called "Self-guided tours", after completing this one we can provide you with many more challenging projects. This project will require full time work of 2-3 developers and a designer for 2-3 months, so please apply only if you're able to provide it. Project description: We are building a platform to connect guides and tourists. Using the platform, guides create interactive self-guided location-based tours. Tourists login on the platform when they go to certain location. They browse all available tours, choose paid or free one and press "Start". The tour begins. On the interactive map they can see their current location, the route they will follow and a list of objects they will visit on their way. At every point of the tour, they can see photos, play videos and listen to voice guidance recorded by the guide. The guide receive a payment for each bought tour. We receive a fee from it. The service consists of two parts: web-service and a mobile app (both for iOS & Android). The website is both for guides and for tourists - guides can create tours there, and tourists can pre-screen all available tours before they will actually use the app. The application is mostly for tourists. The main element of the application and the website is interactive map, where guide can create a route, attach or record a photo, video or his voice. The tourist can see all of these elements as he follows the path (the app should work well with GPS). Authentication is through either social networks or email/password. The app should include multi-merchant online payment processing system. We would like to use rich HTML5 graphics, preferably "material design" for this project. Include your best similar works in your response. Please state your price or price range for the web service and two mobile apps (iOS & Android). Thank you.