The New Zealand company wanted to develop a messenger, in order to create a communication platform on its basis in the future to provide clients with services by specialized specialists.

1. Development of messenger to create communication between experts and clients using text message and voice call mode

2. Integration with payment systems

3. Flexible pricing system for the cost of services calculating

1. First of all, we have analyzed all known external services directed at work with audio/video and chat rooms. During the design stage we have realized that available services do not fully meet both: our requrments and requirments of our customer. Services did not scale well for the necessary functionality. That's why, instead of using the available services/platforms for text messages, it was decided to develop and use its own transport protocol for message exchange. Open libraries of an external service (twillio) were used to implement audio and video calls. And for chat rooms we used websocket connections. For flexible use of the messenger, it was decided to provide three ways of communication: real time chat, voice call, offline chat.

2. Google and Apple payment systems were connected for payment. All purchases take place with the use of the Google billing library, through the Google Play store. In order to provide security, the purchase verification takes place on the server.

3. Based on the concept of different communication types, it was decided to use the following payment methods: pay-per-call payment in conversation mode and payment for work to be done with piece payment.

The result of the first year of work was an application - a messenger, which over time grew into a full Zodia Physics service - a platform for providing services to people by mediums, astrologers and other experts in this field.

The basic functionality is includes search for appropriate expert, replenishment, cash balance update, creation of text or voice chat with the expert.

Firstly, the user should dowload application, upon it he is provided with a field where he can choose a specialist, see the tariffs and the country where the selected specialist is located. Depending on his needs, he can also select the communication method, it may be a video call or chat. If the required expert is offline, the user will receive a message when he comes back to online. Users can replenish their cash balances and pay for services using an attached credit card. Favorite advisers can be bookmarked, allowing the user to find them easily next time. Besides, the client can set up his personal account, receive news and check his balance if he wants. Support service is always ready to help users.

The application spread on a free-of-charge basis, but the expert services provided are paid, the first 3 minutes of the conversation are free, as a bonus, and the payment is charged only after that period of time. The application has the ability to accept push notifications (rich notifications). There is an opportunity to place liked experts in bookmarks for faster search. Besides, each user has the opportunity to set up his personal account, receive news and check his cash balance. Application support multiple languages.

One of this application features is the ability to calculate payment per minute.

Services' restrictions on the use of their products, which made it difficult to implement the possibility of video communication with a specialist.

A socket is used to receive connection between the client and the server to get information in real time.