Check the back-link is do follow or no follow:

[petrarobert002]

1.Ahref is best tool for this work
2.you can also easily check the link is do follow or no follow. Just right click on the link and click on inspect element the check the resource code.It show the link is do follow or no follow.
3.You can also install moz tool which show shows no follow link with red color.

[krishlucas]

Thanks for sharing such type of helpful information.

[appsquare]

Its really a nice and informative post about SEO, thanks for posting such a good post here publically, Mobile app Developers