Naji Jayjay : this is a characteristic mechanism of free to play games. It's effectively partly meant to have the player come back on a daily basis, but it's more than than. At first, the player gets a sense of rapid growth, the game advances fast. The player gets invested into the game, and the game stays rewarding. The gameplay is then artificially slowed down. The player, who has now spent a couple of hours into the game, is now more likely to spend a bit of money to keep the pace going or to compete with other players. And, as you said, it forces the player to come back and check everyday. There are generally many complementary mechanisms, like the player being rewarded for coming back every single day.
Anyway, on mobiles and social networks, the average player tends to spend only a couple minutes per game session. In transports, between to mails... those free to play games are also optimized to give the casual player a bite-sized set of actions to take at multiple time intervals.