Snippets can be used in a layout, so you could create a snippet with a dataview with the current account and go from there. View the images below. The snippet is a snippet with no 'caller'. Only a dataview based on a microflow is present, see image 1. With this you can just put the snippet in the layout, as shown in image 2.
Try these search results:
https://forum.mendix.com/questions/8826/Menucaption-based-on-attributevalue https://forum.mendix.com/questions/4829/Widget-username--logout-ect-like-homemendixcom
You can have a dataview in a Snippet with a microflow as a datasource.
In this microflow retreive (first) an account from your database with
[id = '[%CurrentUser%]']
Now you have access to all account information in this Snippet (which you can place in a layout)
One solution that i have used is to leverage the ideas that have already been shared plus one special widget from the app store.
This can be used for things like the user profile info (like logout), shopping carts, or anything where a nice set of data or list can come in handy. See the widget for more ideas.