Iv had a smartphone and tablet for about 4 years and through that time, apps have come and gone, eventually, you'll stop playing them, here's a list of some that I got stuck on for a while.
Dragonvale - theme park builder, it was whimsical and addictive and I eventually tired of the constant stream of limited edition dragons to breed
Hay Day - it was better than FarmVille, but eventually suffered from repetition. As you advance the cost of machines becomes too expensive and it gets hard to keep up with demands without spending cash
Subway Surfers - like Temple Run, but it makes less sen