I played TCG Pocket for a bit when it first launched, and I like the idea of a mobile version of the TCG (especially since keeping up with the physical TCG can be pretty costly), but it's frankly just not doing anything for me. I'm not a fan of how they simplified the game and changed the emphasis from multilayered strategy to just trying to get your most powerful card into play before the opponent does. I also don't find collecting the digital cards as satisfying as owning physical copies. And, as a mostly story-driven gamer, the fact that TCG Pocket has no storyline makes it difficult for me to find the motivation to play it.
I feel like TCG Pocket is good for offering a casual TCG experience for people who enjoy that kind of thing, but it's just not hitting any right notes for me as it is. Although, I would really love it if they added some sort of single-player campaign mode, because I really enjoyed the Pokemon TCG Game Boy game and I'd go crazy for a modern reimagining.