I'm a big fan of xiangqi (??????), and you're right, there aren't that many great options for solo mobile play - especially for people learning to play. That said, there is one iOS app that comes to mind: "Chinese Chess (Xiangqi)" by Easy 8 Software. This is the link (and no, I'm not affiliated with the developer in any way): https://itunes.apple.com/us/app/chinese ... 43414?mt=8
I'd also recommend the series of books by David H. Li, which starts with "First Syllabus on Xiangqi: Chinese Chess 1". There are a total of 5 books in the series. The first book provides details on playing the game, and the subsequent books focus on strategies for each of the other main pieces (e.g., cannon, horse, etc). Books 3-5 are much harder to find, but the first two books are pretty easy to track down. That said, the first book will be what most starting players will want anyway.