If you gonna start reading a novel that you already know, it's premium.
You will notice that once you get past of half of the chapters released (idk the exact amount) the app will request you to pay spirit stones... Ok Stop right there!
Don't buy that chapter, just wait for the author to release a new chapter and the one you are about to read will get unlocked.
That's the spot for free readers... Basically you will get the same amount of chapters as everyone.
Example: If the author release 2 chapters (ch.99 & ch.100) the chapters 49 & 50 will be free and unlocked.
If you are a casual reader or you are reading a lot of novels, just do that, stay behind.
There is no point of trying to catch the last chapter, after all everyone get the same amount of chapters per day, and you will save your spirt stones for other novels.
GL fellow readers.