CrazyStone DeepLearning Pro 4+

I hesitated buying this for quite a while because of the negative reviews, especially regarding the SGF import/export capability. But I finally took a chance and am happy to say that they have fixed all of those issues. You can copy and paste to/from the clipboard to exchange games with other apps, export via email, load/save from iCloud and Dropbox (and probably other cloud drive apps, those are the only ones I tested), and it also works as an “Open with ...” target for other things like email attachments and web links.

I’d recommend trying the free version of CrazyStone first and seeing if it works for you because the import/export features are the same there. The Pro version adds Analysis mode and Rating mode (which tracks your rating separately for 9x9, 13x13 and 19x19) and removes the ads found in the free version. As others have noted, the UI isn’t the greatest in the world, but it is functional when you get used to it.

Even though it is quite expensive, I’m happy with the purchase, and it is at least much more affordable than the Steam version.

I’ve owned & played CrazyStone for almost 2 years now. Runs seamlessly on iOS, I’m 7-8 kyu and can beat this app at only 6-7 kyu, no lower, so it’s pretty accurately rated. You set the computers strength by Dan-kyu, so great flexibility. It’s much stronger than me if I “open the throttle” on its engine & if you search YTube, can see older vids of BattsGo Dwyrin, Hajin Lee, Hanayeol, and other high Dan players engaging w CrazyStone. Although one can play bots, like OGS, those require internet or cell connection; CS is a standalone app that can be played anywhere without data connection. Simple setting, saves all your games in sgf, can play human v human if you want to play friend & have no real board or are traveling (train, etc). With SmartGo Kifu moving to new subscription format, CS may be the best one-time paid iOS Go app. I love it. No relationship to game creator, just happy customer.

There are stronger apps out there now, but none that track your progress and automatically set up your games against a large selection of difficulty levels like this app. This app and SmartGo basically define my standards for what features I’m looking for in other go apps. Also “A Master of Go” is the strongest native go engine for iPhone... it’s just an iPhone implementation of the Leela Zero engine. I’m not strong enough to benefit from it though, and it’s lacking in features, so I still train on this app