The Inotia 4 Daily Bonus is something you get for opening the store on a daily basis. If you miss 1 day then it resets to the beginning. It will also reset when you have logged in 12 day consecutively.
It’s not much of a bonus though because you can get the same amount of coins in a couple minutes and crystal by doing a few of the many free offers. If you do play everyday though it can be a nice little reward. Check out the Inotia 4 Guide Wiki for all you need to succeed!