Like for those tv apps, in my case, from Spain which will only show certain content if you have a Spanish ip. For me in Germany I thus need some kind of proxy from Spain. Does such an app exist in cydia? Or would there be any other way in order to appear as a Spanish client to the servers of that tv app?
This is a non-Cydia solution. I hope it still applies as answer for your question though.
VyprVPN can be used to bypass website restrictions or bans implemented by certain countries.
I have not tested this app myself, so I cannot "recommend" it as such, but I think based on the information provided it should to the job for you. Good luck!