I would like to pose this question at both a general (see title) and specific level (see below).
I am soon to graduate university with a Computer Science degree. For the last four years I have been operating a sole proprietorship creating iOS Applications, both self-designed and contracted work. The result has been several Apps published on the App store and modest income from this work, generally.
Following the conclusion of my university degree, I would like to apply for jobs/graduate programs at some larger companies. However many job listings understandably call for "x years professional experience".
My question therefore is: does owning and operating a sole proprietorship in this fashion count as "professional experience"?