2D Game level editor website (with Firebase backend)

Please do NOT place a bid, if you plan to change your price in the future. We will NOT accept any changes, at any time, for any reasons. Please read the specification carefully and only make your bid if you understand what we need and you are capable to implement it. We accept only a FINAL price. Thanks! Specification: We need a website which works as a game level editor. The game is a 2D world building (sandbox) video game for iOS. The website should only be capable to edit the 2D levels. Nothing else. So the website will not be able to run the game, just edit the levels. A 2D levels are built from a 32x32 grid. A grid items are 30x30 pixel size. The game level editor should be able to place these 30x30 pixel size items on the 32x32 grid. The game level also have a background image, which should be displayed in the game level editor. The game level grid information should be loaded and saved to Firebase. The images can be stored on the web server. Steps 1., The user need to be logged in before doing anything on the site (user auth should be handled by Firebase). 2., The user can create a new level or load an existing one. 3., The user can select or change the the background image. 4., The user can select and place items on the 32x32 grid which are displayed front of the background. 5., The user can save or discard the changes. 6., The user can log out. There are maximum 10 background images. There are maximum 1000 item images. The number of leves are not limited. The Firebase database structure is predefined, but it's pretty straight forward. All items has a unique identifier and all info is saved as a string. The website should also work on desktop and on mobile as well (responsive design). It should work on the following platforms: iOS, Windows, Mac. And it should work in the following bowsers: Google Chrome. The code must be clean, well structured and mostly commented/documented. Of course less comment/document is needed if the code is super obvious and super clean. Any third party libraries or frameworks can be used (either free or paid). We can make milestones as you like, but any milestone deposit will only be released after the milestone assigned, 100% working source code is delivered for us. No prepayment will be made for any reasons. Thanks! KZ