Your phone weighs much more than the vinyl and slows down your table. When you put the vinyl on it run too fast.
Speed accuracy- how accurate is accurate?
Certainly, running at 33.333333333333 . . . with a stylus in the groove is ideal. Running an iPhone app I just discovered (RPM), I'm running about 33.55 or 33.56. Table is an LP12 with an 18 year old Lingo. Everything sounds OK- is it ok?