A Login / Register screen (with Facebook and Gmail add-on)

Hello there, You probably know what this small project is about with the title. We need a first login/register screen when the app is launched, following those specifications: 1) The code has to be written in C# and developped/compatible with Unity (free software) 2) The user can register with his facebook account, with his google account or with his email-adress. When the user click on the "Create an account" (whatever the way he uses), it goes to a new screen that ask for a pseudo, a password, repeat password. The user can then confirm his account creation. It then goes to a new screen that display the field "amount" that is linked to this player account (see 6)). 3) If the user is logged, it is always logged and disconnect only if it disconnect (see it as any app like whatsapp, tinder or any online game, you don't need to log in everytime you launch your app) 4) On the bottom right side, there is a setting button that display a little window with the option "disconnect" 5) You are in charge of the database to handle the accounts, password, emails, etc. You need to create this database and provide it with the code when the project is done. 6) The specific field "amount" is a certain column in a table unrelated to the infos of the player but which is linked to the account ID. It contains the number of connections the users did in total (so it's incrementing each time a user disconnect then reconnect or connect from another device). This information is displayed when the player successfully is logged or registered correctly (in this case, the amount should be 1 since it's the first connection). Controls on registration : a) email addresses format has to be valid and shouldn't be already in use b) pseudo shouldn't be already taken and has to be valid ( lenght > 20 characters ; no numbers) c) password and repeat password should match and have a minimum of 4 characters max 12 d) if the registration is a success, it is stored in the database as a new account with an unique (incremented) account ID : INT(9). Thanks and see you around! ;)