I recommend Smart DNS Proxy or KeepSolid SmartDNS - both work with iplayer, Netflix and most other UK channels, don't slow down your connection and are dirt cheap.
KeepSolid SmartDNS cost me $28 through Stacksocial with code DN30 for a lifetime license.
www.stacksocial.com/sales/keepsolid-smartdns-lifetime-subscription
Smart DNS Proxy (
www.smartdnsproxy.com/) cost me about $35 for two years through a promo link I can't find at the moment.
It has slightly more features than KeepSolid and works for live BBC channels too.
Like the guy above said, VPN Unlimited also works for iPlayer. It's not as good a VPN as Windscribe, but you can get a lifetime license for pretty cheap.
But VPNs are too much hassle for streaming. If you use the YogaDNS app it's possible to configure your computer to use secure DNS (I use NextDNS) all the time except when you visit sites you want to stream from, at which point it switches to SmartDNS, although that does take a bit of work. More simply you can just use a program like NetSetMan to switch between DNS providers whenever you want.