extend android project

android developer proficient with dagger 2 I have a chat application i need an subscription service build in. the application is not available on Google play so it needs to be a custom build system - on activation app needs to register to an external database via rest api offering a uniqueId. - on the app needs to check periodically if the subscription is still valid via api - if subscription is expired app needs to lock - needs an subscription information page which shows the remainder of the subscription let me know what other information you need