Here are the steps you need to follow in order to get started with the App42 platform
Register with the App42 platform
Create an app once you are on the Quick-start page (after registration)
If you are already registered, login to the AppHQ console and create an App from the App Manager -> Create App link.
Once the App is created, you will get an ApiKey/SecretKey that you will use in your app for initialization of the SDK.
Download Unity SDK
Unzip the downloaded Zip file, the unzipped folder contains App42_Unity3D_SDK-x.x.dll (inside x.x/App42-Unity3D-SDK folder) and App42_Unity3D_SDK_WP8-x.x.dll (inside x.x/App42-Unity3D-SDK-WP8 folder)
If you are building your project on Windows Phone, you have to use App42_Unity3D_SDK_WP8-x.x.dll and for rest of the platforms App42_Unity3D_SDK-x.x.dll should be used.
Import required App42 dll as stated above in Assets folder of your Unity Project.
Downloaded folder contains sample project too which can be used as a boiler plate project for the Unity application. Please see README for instructions to run this sample.
You have to instantiate ServiceAPI class and pass your ApiKey/SecretKey to initialize the SDK.
Once you have initialized your SDK with the API Key/SecretKey you have to build the target service that you want to use in your app. User Service can be built with the following snippet. Similarly you can build other services with the same notation. Want to know about all the services of App42 Platform? Click Here
Go To Creating App User for learning App User Management
Go To Saving App Data to learn about App Data Storage.