This is a Thursday ripple effect puzzle. The black cells are cells in which no number should go.
The reason I didn’t make a rules page for this, is because I’ve only ever seen this puzzle on Nikoli and they have the cool flash animation rules.
This is my favorite tetromino, because its two planar forms, J and L, form my initials! (Its number 1, just like the number 1 that appears in the grid)