Rentalutions, Radiator Labs, Social Sign.in, Notion and Optii Solutions named first 2015 cohort participants at event in ICSC’s Manhattan headquarters NEW YORK, 2015-8-27— /EPR Retail News/ — MetaProp NYC, the New York real estate technology accelerator, signed an agreement with the International Council of Shopping Centers (ICSC) and announced its initial 2015/2016 cohort participants at an invitation only event with more…