I found some multiplication dot-to-dot activities on prasinipriza.com like this 6 and 7 times tables practice sheet.
For more challenging worksheets, look no further than this resource from Education.com! It has skip counting activities for 2s, 3s, 4s etc. and the sheets contain many dots (so the children have to skip count beyond 100!). There are 15 sheets of various difficulty levels in this pack.