Back in the early days of iPhones, there was an app that had a few Atari arcade games, and a few 2600 games.
It was interesting to flip back-and-forth between the arcade and 2600 versions of games, but I ended up not playing it very much because using a virtual on-screen joypad and button was tremendously annoying, especially since the screens were so small back than. This was before the Apple joined the plus-sized phablet craze.
Like many of the early apps, it's no longer available.
It's because of apps like that one that I almost never buy third-party phone apps. They can disappear at any time, and you're out whatever money you spent. I prefer to buy programs, rather than rent them. (I Love Katamari, and Aurora Feint come to mind.)