The "Czech Step by Step 1" textbook is probably the most popular textbook of Czech for foreigners on the market. You will receive a CD with the textbook, and the recordings are also available free of charge on the website www.czechstepbystep.cz or on the Czech Step by Step channel.
But you will definitely appreciate this application, thanks to which you can have the recordings available offline and clearly arranged, so that you can quickly find the one you need for yourself or your students.
This app contains CD 2, i.e. recordings from lessons 13-24.