Generalizing the topic, does anyone know if there is a map of subjects/branches in mathematics and books/blogs/etc giving examples of real-world applications?

Generalizing the topic, does anyone know if there is a map of subjects/branches in mathematics and books/blogs/etc giving examples of real-world applications? Personally, I know the (existence of the) maths behind some applications (e.g. JPEG -> DCT) because I have learned it while at uni, but in general, if I encounter a mathematical subject I struggle to find examples of its application.