Are there any working Form Modules in Drupal 8 yet? Webform doesn't work yet. Eform won't send emails yet (because rules isn't ready yet). Drupal's built in Contact form sends an email but doesn't save the entries or let you redirect to a thank you page.

Basically I need form builder that saves the results and sends an email - like webform in D7

Is there anything I'm missing or do I just have to wait?
As of 29 mar 2016, there is a dev version of webform, but they're not confident in it enough even to publish it as dev: https://www.drupal.org/node/7404/release?api_version%5B%5D=7234

There's also eform, which is a D8 version of the entityform module: https://www.drupal.org/project/eform

When you're digging through dev versions, a good metric is looking at how many people are using that version-- check the per-version usage stats.  Ideally you want thousands or tens of thousands of sites reporting, but we're not there yet.

For now, I'm hacking the d8's core contact module.  I hope that a more complete solution will be available soon.

People who say you shouldn't use dev modules on production sites are living in the past.  Drupal 7 would have been functionally unusable to a huge chunk of its user base for a long time if no one put dev modules into production.  There are still dev modules that are integral to the function of thousands of substantial d7 sites.  Drupal 8 is nothing but a toy without relying on dev modules-- the form question being an excellent illustration.