Stockholders' equity (deficit) (Tables)

6 Months Ended

Jun. 30, 2015

Stockholders' Equity Note [Abstract]

Schedule of allocation of share-based compensation expense

The allocation of share-based compensation expense by operating expenses is as follows:

		Three months ended June 30,
		2015		2014
Research and development	$	70,228	$	5,975
General and administrative		199,179		19,818
Sales and marketing		50,681		760
	$	320,088	$	26,553

		Six months ended June 30,
		2015		2014
Research and development	$	106,684	$	12,069
General and administrative		282,478		41,878
Sales and marketing		521,529		1,533
	$	910,691	$	55,480