ヒーローメーカー

If you leave it idle, you get idle rewards? I guess you could call them that. You can earn rewards even when the app isn't open, so it's recommended for people who don't have much time! I downloaded it for point-gathering purposes, so I haven't played it thoroughly yet, but I plan to play a bit more.

If you leave it idle, the coins for growth will naturally increase, and you can use them to strengthen your weapons.