What is happening? – Tsumego Pro (Go problems) Review

Maybe it’s because I am a beginner in Go, but I just don’t get it. The app just has some inbuilt problems, and no explanations at all. What does it mean to solve a problem? When is it solved? What is the problem at all? There are just some predefined moves which are need to be made for some unknown reason and if you are not following them, you are wrong. Maybe some instructions would help.
Review by SexWithAWhaleInc on Tsumego Pro (Go problems).