You are correct Two Plugs, successor, was the wrong word to use, perhaps 'new version' would have been better.
I too was a user and fan of Tyre and like you, paid for a license.
I became a basic member of MyRoute-app and followed it for a while and I was impressed with what I saw. Like Tyre, it works seamlessly with Tomtom and but has the advantage of 'multi-mapping' one of which is the Tomtom maps (for Gold members). Because it is web based, the potential for it's development is huge. It is more community based and has just introduced a 'groups' feature for like minded users to share routes or swap stories.
I took advantage of a discount for anyone with a Tyre license to sign up for a Lifetime Gold membership. I urge you to give it a try, you won't regret it.