All good services and a lot of smart TV's have these players already built into them. They consume about 4 Mb of Download bandwidth when running in Standard Resolution, but will consume considerably more when running in higher resolution modes, so if you are having buffering problems then consider dropping down to a lower resolution. Also make sure you use a good Internet supplier, like www.netseekers.net and please be also aware that some of the above services, are actively blocked from being used outside of their native country. You can get around this blocking problem, by using a VPN service, I use https://www.smartdnsproxy.com/ but please be aware this service involves you making changes to the DNS settings within the router you are using. Their web site has good information on how to make these changes, but this is not something we can help you with. Plus when the service you are viewing changes IP address, you have to make changes to the router DNS settings again. Also be aware that a VPN service introduces another link into the chain of the internet signal getting to your house. A poor VPN service, will cause picture buffering problems, which look like they are the fault of the internet service provider, who are actually innocent. Also, some of the services listed at the top of this page are now getting more clever at spotting which IP addresses are actually those of VPN services, and targeting them for blocking. My advice would be to use the service shown below, where no VPN is required.
The Future Of Legal UK TV in Spain Is