xxx.onewaytextlinks.xxx anyone used them?

xxx.onewaytextlinks.xxx

this site gives allow free directory submission manually .they are giving their software free .but in return we have to write their code in our website.Does it cause harm to my webiste or my google adsense account.Is it the save way to go?

Never got much return when I did it back in the day and google are quite wise to this kinda thing. Didn't hurt my old sites just didn't do much for them.