I see things got solved allready when i was looking in to your cap. I post my cap anywayz.
https://
drive.google.com/open?id=0B1SSuCVV8v74ZTdZZmQ1QTNTS00
Still, when i see the arrays, there a lot of dots created. In fact, to much. Many on the same place. That will have an impact on the save/load times.
Mayby you should do two things in your code.
1/ When the touch speed is very low, dont make new dots, just grow the last one made in size.
2/ Dont make a new dot when the touch is overlapping an old dot.