Kotlin - Implementation of "off line" functionality in an existing application

Inform: for this task, I hired one India developer before and he has been working, but he didn't complete all due to his personal problem. You have to continue his working and about the details, it will be discussed by private message. The original task's spec that I assigned to him: "I have an app already developed and productive. The app consumes data through an api for and generates entries to the db also through the api. I need to: When there is an available data connection: 1. Store the data that is required within the app in local tables 2. Validate whether there is event data in the local tables for sending data pending sending and execute the call to the api to send them. When there is no data connection: 1. It is possible to work in the app using the data from the local tables 2. Events can be recorded with their data that include photos, video, audio and GPS locally so that they can later be sent to the database through the api. All the functionality for data capture, implementation of video, audio, photography, etc. is already developed. It will not be necessary to do it again. I use bitbucket for version control and development." PS: this can be opportunity for long-term project. Please add "App-Kotlin" at the begining of your proposal."