Anybody know of some alternate "root" apps or sites for phones

When the standard ones don't work? I read that some phones make it damn near impossible to do and I've tried all the main ones like Kingoroot but nothing works. I'm trying to use Dr Fone to recover some texts that I accidentally deleted, the other fricky part is with My Verizon I've always had every text I've ever sent or received on the site but for some reason they only go up to the last 3 days, strange. Phone is a ZTE Z839. Thanks in advance