Mini-karaoke Android feature using Unity Audio

General information for the business: Adding LYFE to private & community events
Kind of development: Customization of existing program
Num. of modules: 3
Description of every module: There are 3 main functional modules
1. Player - Select an audio /video track & listen to it. Standard playback controls.
2. Recorder - Record your voice on top of the selected audio track
3. Mixer - Mix the recorded & background audio track and add simple DSP effects - compression, reverb

In terms of code it would break down to the following
1. Android to Unity & back - Calling Unity from Android using UnityNativePlayerActivity or similar. Passing the context correctly & managing the activity backstack
2. Unity UI to create the screens as per the attachment
3. Unity Audio to use the audio functionality - playback, recording, mixing & DSP

Attached doc contains rough wireframes.
Description of requirements/functionality: This requirement is a ‘mini-project’ in Unity.

We need a simple "overdubbing" / "karaoke" Android app. This is not a game & there is no score. Think of it as voice notes with some background pre-recorded audio tracks (mostly music). This isn't Dubsmash. Its a simple voice recorder & mixer where a user can add their voice on top of an existing audio track.

You would use Unity UI & Audio to create a standalone app with the following functionality

Screen / Android Activity 1 - A simple list where you choose a background audio or video track
Screen / Android Activity 2 - The track starts playing (when you hit the play / REC button) and you dub your voice on top of the background track
Screen / Android Activity 3 - You mix the 2 tracks together (background + recorded voice) and apply some basic DSP (primarily reverb & compression)

This is actually one small feature in our product. We will do the integration - you can create a standalone Android project. Familiarity with Unity UI & Audio should be sufficient but you will also need to know how to integrate Unity into an Android application (using AndroidNativePlayerActivity or other suitable approaches). The most important thing to note is that we want to use the build process of Android Studio & Gradle and therefore Unity should be a library within the Android App.

This requirement is meant to be a basic recorder and mixer that allows you to record your voice on top of an existing background track. You can think of it as a very basic karaoke (without fancy features like score or pitch comparison with the actual singer). So in short you record your voice on a background track, mix them together using the Unity Audio mixer functionality and save the recorded file to device storage.

The reason we want to do this in Unity is because we want to use Unity for other features as well.
Specific technologies required: Unity game engine
Extra notes: For more info on the product visit
http://lyfe.events (Product site - under development)

Final deliverable needs to be a project that can be built in Android Studio, using Gradle. Support for API versions 14 to 23 expected.