Lucas Chess is a free program for Windows which includes 36 engines with ratings ranging from 1300 to 3000.  It also has a bunch of tactical puzzles and training features.

https://www-lucaschess.rhcloud.com/

Nagaskaki is also free and for Windows, and has ten or so levels ranging from 1472-2300.

For iOS or Android, there is also Remi Coulon's The Chess Crazy Bishop which is free and has 100 levels ranging from 258-2300.