Need to Add Facebook challenge, Facebook Invite & Facebook Leaderboard in a 2D game of Unity3d

(Note: Please keep in mind the Subway Surfer game while reading these all points. because few years back, subway surfer had the option for users to challenge others along with FB LeaderBaord. Now, only FB LeaderBaord, they are using.) Read the instructions carefully and then bid. If you said to increase the budget amount in the messages, you'll not be awarded the work. I'd like to work with the person, who have the experience of all below mentioned functions or he must know how to implement these below asked functions. I'll only chat with the selected person on the functions, i'll consider your bid amount or my offered amount final for this work, whichever is lower. One special instruction, you must use Unity3d 5.5.0f3 for this. I needed someone, with whom, i can work, so i can add Notification System, Daily Challenge System for the game along with FB Invite, FB Challenge & FB LeaderBoard Option; 1. Game Notification System: I want to add Game Notification SYstem, just like it's added in the Subway Surfer Game. 2. Daily Challenge System: It'll be predefined system in the game, it'll change the words daily. These words, user have to collect it's alphabets from the game to complete that word and win the daily challenge. This option will give the user free coins as pre defined upto seven day & they will award the users bundle of coins on daily basis and will increase upto seven day continuosly. if user skip one day (if user did not play continuously seven days, he skipped at any day, like day 2, day3 or anyother) then this countdown will start from 1st day but with a new word for daily challenge. 3. Facebook Invite: When the user click on the invite button at Main Menu of the game, the new window pop up which asks him to login his facebook account. When he logged in, he'll see the list of his facebook friends and a selection checkbox, via which he can select from his friends list to send them invitation to download that game. When he selected all the wanted freinds, who he wanted to select, then a new window pop up, in which all the friends ids selected will be shown in above bar, with a prewritten subject line and a prewritten message in the message box. The user only have to click send, so that message will be sent to the invited facebook users that, "ABC has invited you to download and play the XYZ Game from Store. [login to view URL] Challenege; When the user click on the Challenge button at Main Menu of the game, the new window pop up which asks him to login his facebook account. When he logged in, he'll see the list of his facebook friends and a selection checkbox, via which he can select from his friends list to send them invitation to download that game. When he selected all the wanted freinds, who he wanted to select, then a new window pop up, in which all the friends ids selected will be shown in above bar, with a prewritten subject line and a prewritten message in the message box. The user only have to click send, so that message will be sent to the challenged facebook users that, "ABC has challenged you to beat his score in the XYZ Game. 5. Facebook Leaderboard; IF the user did not logged in facebook, in his game, then he'll see the users from Google Play Store's LeaderBoard ( this leaderboard will show via the LeaderBoard option of the Developer Console Account of Developer). But if user click on facebook login on any option of FB Invite or FB Challenge or in this LeaderBoard, there will be option of Friends, he will have to login his facebook, so he'll see his friends in the list that how much highest score they have been done in this game. If his friends didn't downloaded or played this game yet, then here, there will be option of FB Challenge button, via which user can challenge his facebook friends to download and play this game.