Onsen is another Angular based mobile UI framework, and this one actually (I checked, honestly) does have its CSS framework based on TopCoat, although they have modified it a fair bit. It hails from Japan (Onsen means Hotsprings or Spa in Japanese, so the name is cute pun) which may explain why it lacks the exposure of Ionic.
I just got a new computer, and joy of joys it came with Windows 8.1. I was seriously considering downgrading (upgrading?) to Windows 7, but I figured that if I was going to stay in the Windows world for a little while I would have to get use to direction that Windows was going and I would tough it out with Windows 8.1.
Ionic is the new hotness in the hybrid app development world, picking up steam and popularity at I high rate. It uses Angular to allow for declarative, interactive pages and their own CSS UI to create a modern looking UI. To this, Ionic adds its own special sauce: a collection of Angular directives, a CLI tool, some libraries and proscriptive structure for creating a mobile application.
Before I go too deep down this rat/rabbit hole, I should state that Libraries are what has allowed programming to develop from where only the best of the best can produce software to a place where a plumber like me can still produce some pretty amazing stuff.
KendoUI is one the most popular mobile frameworks around, and for good reason. Until a few months ago it had a commercial only license which limited its attractiveness to non-enterprise developers, but its new Apache license makes it very attractive especially if you are looking for a framework that heavily leverages jQuery.