Share to speech, the leading text to speech app in the Windows Store (link) is updated to natively support Windows 10. It is redesigned from the ground up with the aim not to improve just looks but also usability, and to make it a modern app that can scale to all window/screen sizes. Currently it is not yet released for Windows 10 Mobile as it requires some more testing due to pretty bad current performance of Windows 10 Mobile on low end devices, but you can always continue using current 8.1 version until it is fully ready. Here are some pictures:
Facebook
Twitter
Instagram