We started with Chess Tactics for Beginners, which is geared for students from 300 to 1000. Then we worked on Chess School (no longer available), Chess Tactics for Intermediate Players, and CT*Art. I myself had done the CT*Art for 3 times. I never tried the Seven Circles recommended in the book. In my mind, it's close to insane and very unlikely we could execute it. We also did several other software from ChessOK, mating, endgames, studies, opening lab, and etc.
Nowadays, all software have their app version. ChessOK (aka ChessKing or ChessQueen) has published more than 40 chess apps. They are also offered as subscription: https://learn.chessking.com/learning/purchases/subscriptions-info
I didn't improve 700 in 2 years, but I went from 1326 to 2034 in 11 years.