Overall I've heard respectable things about Clash, but it didn't get my interest in time.
World of Tanks Generals was the heir to my mobile card game throne after Hearthstone refused to load on my iPad. Wonderful game, as far as I am concerned. The grind feels pretty small compared to Hearthstone, which is a definite plus, but it doesn't have the card variety. I play WoT already, so Generals was a fun extension of that genre for me.