What are some websites that offer native English speakers to teach English conversation or accent reduction by phone or Skype?

Try ClassDo, it's a community of teachers and students from90 countries. You can find a lot of native English speakers from US, UK, Australia, New Zealand etc. https://classdo.com  Teachers charge differently according to their level of experience, so you can find one that would suit your budget (do a free trial lesson to find a teacher you like).