Fit The Blocks description

Drop blocks onto the base in 3D. Start with the easy puzzles, simple sets of blocks to cover up the base. Work up to the harder levels where the blocks may need to be rotated and finally the ultimate challenge - solve the multi-level puzzles.

There are 80 levels to play for free. Really free - no adverts. If you complete those and want more, then there is a single in-app payment to unlock another 320.

If you need hints you can buy packs of 50, but I bet you're smart enough not to need those...