The Pokémon Trading Card Game just showed up on Canada's iOS app store. This means that it's likely heading to other territories soon too. The Pokemon Company announced it during the Pokemon World Championships last month. For now it's iPad-only, but it syncs up with the long-running desktop version.
Here the first details of what this version includes, if you're curious:
Interestingly, this is apparently version 2.23.0 despite the iPad version being brand new, though presumably that's because the desktop version's been around for a bit.