The app you are looking for is called File Brick. Oh, and Emi, I don't really understand what you are trying to tell me about the problem you had with the old system. Whatever, the problem with the new system is that it is completely pointless except for using Onedrive as a backup device. Through the new system you cannot access files on Onedrive at all, in any way, unless you use the web site. Sure, you can automatically backup your files to Onedrive, but you can't access them. Also, if you mistakenly erase the PC copy of the file it will automatically erase your backup on Onedrive??? How's that even useful as a backup?
Anyone with any brains keeps a local backup of their local files via File History or somesuch. Onedrive is useful because you can store things separately from your PC which is highly useful for tablets and other limited storage devices. Or at least it was. Now Onedrive sucks up all the storage space on your device, making it 100% useless.
Unless you use a third party solution, because MS have failed to provide one. Hence, File Brick.