List of links with instructions for manual testing.
Check that marker appears at:
http://www.openstreetmap.org/?lon=37.616436&lat=55.757144&zoom=16&mlat=55.757144&mlon=37.616436
You may have to do it from Incognito mode if new style Google Maps are enabled for you.
https://www.google.com/maps/@47.502359,33.903809,7z
Zoom out to have non-integer zoom, make sure that it still works.
https://foursquare.com/v/red-square/4bb3345942959c74d79d212c
Must show message "Browse to place page":
https://foursquare.com/dudarev_ru/checkin/51ed39b5498e2ce0f6b6509e
http://www.bing.com/maps/?cp=55.75426449918814~37.62019157409668&lvl=16
http://wikimapia.org/#lang=ru&lat=55.757110&lon=37.616430&z=16&m=b
http://2gis.ua/dnepropetrovsk/center/35.010166%2C48.494881/zoom/13