Compare Two Sequence To Find The Maximum Similarity

We know BLAST can compare two sequences, however it compares sequences by lining up them. My question is can we shift one sequence then compare the other. Let me give you a simple example:the length is 15

GTTCCTAGTCTAGAC
TCCTAGTCTAGACTT

If we shift it and compare

GTTCCTAGTCTAGAC
  |||||||||||||
  TCCTAGTCTAGACTT

Then there are 11 letters hit, we define the score by 11/15=73%. Of course, we can shift to whatever we want. How to find the max score? Is there such a software to do it? Thanks.