The best replacement for sipgate is callcentric.

The best alternatives to sipgate are rated as following:
★★★★★  callcentric
★★★★  voipfone
★★★★  ipkall
★★★  gizmo5
★  easybell
★  nfon
★  dus.net
★  gizmo
  placetel

Your alternative for sipgate is not listed? Suggest!
Speaking about sipgate, one probably shouldn't forget about google voice.

Other search terms related to sipgate and their ratings are:
★★★★★ google voice
★★★ freepbx
★ sipdroid
You have in mind a companion for sipgate and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of sipgate in all years. Click on graph for more.
sipgate
callcentric
voipfone