what tool is the quickest for backlinks

if you want in budget:
Get GSA and Scrapebox.

Else many other available like RankerX,Senuke etc

Manual link building is the best always.

Try that software: https://seo-autopilot.eu. I tested it and it is very good. You can create entire tier,1,23 structures.

I've had a try with seo autopilot and liked it a lot. for me though, the monthly subscription is a bit high in comparison to Rankerx. But definitely worth a look. I think any one time fee tools like scrapebox and GSA is a good place to start. At least there you wont have to worry about recurring subscription fees.

Also as other said - scrapebox is insanely universal.

I always suggest RankerX if you want to create high authority backlinks for Web 2.0 blog / Web 2.0 Profile/ Bookmarking/PDF or Wiki
And GSA if you want to create backlinks for Webprofile/Guestbook/Image Comment /...