New York, Mar 27 (IANS): Grindr, the worlds largest gay dating app, is set to change its software this week to urge millions of users to get frequent HIV tests, in an an effort to shrink the global epidemic, the media reported.

Grindr, which claims to have 3.3 million daily users from every country in the world, will send men who opt into the service a reminder every three to six months, and simultaneously point them to the nearest testing site, The New York Times reported.

It will also let clinics, gay community centres and other testing sites advertise for free.

The company is making the move to "reduce HIV transmission and support our whole community - regardless of HIV status - in living long and fulfilling lives", Jack Harrison-Quintana, Grindr's director for equality, said on Monday.

HIV experts greeted the announcement enthusiastically.

"Wow, that's great! For a company of this magnitude to do this is groundbreaking," said Jeffrey D. Klausner, a former chief of sexually transmitted disease prevention in San Francisco who has used Grindr to promote testing.

Perry N. Halkitis, dean of the Rutgers School of Public Health and an expert in gay male behaviour, called the decision "excellent".

Jonathan Mermin, chief of AIDS and sexually transmitted diseases at the Centres for Disease Control and Prevention, said many men who use location-based phone apps to find other men nearby are considered at high risk of getting infected.

Therefore, "all effective efforts to increase testing are welcome", The New York Times quoted Mermin as saying.

The Centre recommends that sexually active gay men get tested at least once a year and those at highest risk get tested every three to six months.

More than 107,000 gay and bisexual men in the US have HIV but do not know it, according to Mermin.