Stockholders' equity (deficit) (Tables)

9 Months Ended

Sep. 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 September 30,
		2015		2014
Research and development	$	59,688	$	1,528
General and administrative		156,236		22,460
Sales and marketing		45,616		989
	$	261,540	$	24,977

	Nine months ended September 30,
	2015		2014
Research and development	$	161,819	$	3,903
General and administrative		443,267		74,032
Sales and marketing		567,145		2,522
	$	1,172,231	$	80,457