This app was mentioned in 15 comments, with an average of 1.53 upvotes
Earthcore that just came out has a very nice campaign. The AI is quite good and challenging. IMO it's one of the good TCG that came out recently.
https://play.google.com/store/apps/details?id=com.tequilagames.elementsfree
Earthcore: Shattered Elements is one of my go to games. It's not p2w and is very generous with booster packs and in game currency.
I recently started playing Earthcore: Shattered Elements and I've been quite impressed with it. I saw it suggested in another reddit post and thought I'd give it a shot. It's free to play with generous payouts so you can definitely get buy without IAPs but they are there if you want to buy some card packs. They also have a subreddit over at /r/Earthcore which I believe is maintained by the devs so if you had any questions or problems they should be able to help. Also, according to the sidebar of their subreddit, it's coming to PC at some point as well.
Someone above mentions Earthcore:Shattered Elements. I've played it a little and it seemed okay, but didn't really ensnare me.
Earthcore: Shattered Elements Most in depth TCG on mobile. If you are looking for a challenging game with deckbuilding. https://play.google.com/store/apps/details?id=com.tequilagames.elementsfree
Battlehand : RPG/TCG, you can level up your card, there's a fairly long campaign and arena. https://play.google.com/store/apps/details?id=com.kongregate.mobile.battlehand.google
Card King: Dragon Wars Another good TCG/RPG https://play.google.com/store/apps/details?id=com.cardking.dw_iap
Shadow Era https://play.google.com/store/apps/details?id=com.wulven.shadowera
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Edit: This should work
Earthcore: Shattered Elements is very good imo.
https://play.google.com/store/apps/details?id=com.tequilagames.elementsfree