Search - A search tool can be easily added to any Jimdo website using Google's free Custom Search Engine.

Subscribe - You can create a subscribe option for a blog created with Jimdo that will allow visitors to subscribe to get updates from that blogpost with an RSS reader.  You could also add newsletter subscription widgets with a tool like MailChimp that can be easily embedded into a Jimdo website. 

Sign up - Jimdo does not have a system for user accounts for our customer’s websites. We do have password protected areas, but that just means that certain pages are behind a password wall, and there is only one password that EVERYONE uses. No one gets individual usernames and passwords. 

Store - Included with every Jimdo website (JimdoFree limited to selling 5 items at once, JimdoPro limited to selling 15 items at once, JimdoBusiness allows unlimited items, but it gets difficult to manage for more than a few hundred). The store only works for services and real-world physical items. http://support.jimdo.com/store

Digital items are not supported (can’t sell mp3’s or pdfs easily because there is no digital delivery system in place). For digital sales, we recommend using Gumroad and embedding the items into the Jimdo website - note this does not tie into the Jimdo store shopping cart or checkout system; it is entirely a standalone third-party solution that is just viewable from the Jimdo website. 

Terms of Service - This is automatically created for a Jimdo website as soon as they add their first store item and can be edited in the settings at Settings > Store > Terms, Return Policy, etc.

Accepting Credit Cards - Stripe and PayPal are built into the Jimdo store. In fact, many places, it is the only way to accept online payments with a Jimdo store. You can also add standalone PayPal Buy Now or Donate buttons, or even do a recurring donation.

Forum - https://muut.com/ will allow you to embed an entire forum system on your website (I wouldn’t recommend this to someone who primarily was looking to start a website that is exclusively a forum though).  http://blog.jimdo.com/tip-add-a-forum-to-your-jimdo-site/

Live Chat on page - This is possible using a paid third-party tool called SnapEngage - http://help.snapengage.com/how-to-add-the-snapengage-javascript-to-your-jimdo-page/