Android App - It will connect to our websites API

App requirements: 1- login screen: allows users to sign in, the username and password is sent to an API which success/failure username/password is saved in the local storage of the App and are sent in headers of the HTTP APIs Make another API call to get the phone numbers the client has already purchased. This would return a list of phone number with their SIP credentials. this should be saved in the local storage. 2- Dialer Allows users to dial a phone number(TO number), The user should be able to select which purchased phone number they want to use to make the call(FROM number or caller ID) When the call is dialed, an HTTP request is made to the API to check if the call is allowed or not. the call is connected by the SIP credentials of the phone number the user has selected. The android default SIP library is used for this task. At the end of the call, the call data like call duration etc is sent to the API 3- Call logs When a new call comes in through mobile carrier or SIP, the call data is forwarded to the API the user should be able to call any number in the call logs using SIP only. 4- Contacts Users should be able to see their saved contacts in the phone and make calls to them using SIP 5- incoming call through SIP The app should be running and background and all the SIP credentials are used to connect to them. This way a new incoming call is received by the SIP library. when a new comes in through SIP, show a call notification and allow the user to connect the call the call data is sent to the API 6- messaging The user should be able to see his previous messages which are fetched using the APIs the user should be able to send a new message using the APIs the user should see incoming message notification. This is done using [login to view URL] library, which listens to the events [login to view URL] 7- permissions The app should have the capability to be set as the default call handler because this is necessary to gain access to call logs and sms permissions The developer should provide a list of permissions which are needed before starting the development, so we can double check that we will be allowed those permissions by google play store. The APIs will be provided to you, SIP endpoints will be provided to you, the [login to view URL] server for sending events is already done. your job is to create the android activities and layouts. and then use the open source HTTP libraries to make API calls, use default android SIP library to make and receive calls and use [login to view URL] library to listen to new message event and show notification. Even though it looks complicated at first look, the application is very simple. You can use kotlin or java it is your choice. Skills required: Android studio, java/kotlin, making HTTP APIs, using SIP library in android, using [login to view URL] library in android [login to view URL]