Statements of Operations (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 3,546,680	$ 3,389,427	$ 12,162,861	$ 8,312,096
Cost of revenues	2,040,997	2,031,823	7,378,001	5,086,706
Gross profit	1,505,683	1,357,604	4,784,860	3,225,390
Operating expenses:
Research and development	840,577	1,202,651	2,621,445	3,487,291
Sales and marketing	2,919,504	2,959,311	8,436,497	8,199,469
General and administrative	1,258,466	1,165,815	3,925,595	3,882,461
Total operating expenses	5,018,547	5,327,777	14,983,537	15,569,221
Loss from operations	(3,512,864)	(3,970,173)	(10,198,677)	(12,343,831)
Interest income	3,554	5,772	11,018	17,030
Change in fair value of warrant liability	327	56,248	208,480	227,873
Net loss	(3,508,983)	(3,908,153)	(9,979,179)	(12,098,928)
Net loss applicable to common stockholders:
Deemed dividends attributable to preferred shareholders	(2,833,098)	0	(6,874,780)	(19,846,377)
Net loss applicable to common stockholders	$ (6,342,081)	$ (3,908,153)	$ (16,853,959)	$ (31,945,305)
Net loss per common share applicable to common stockholders, basic and diluted (in dollars per share)	$ (3.11)	$ (6.11)	$ (11.62)	$ (56.09)
Weighted average number of common shares outstanding, basic and diluted (in shares)	2,036,117	639,512	1,450,237	569,555