I have ended up with a number of accounts in all sorts of different places which are a hassle to chase individually.
My wife as well likes to see everything in one place.
Is there good software which will link to all my accounts and then display them in one window or App?
Bank accounts mainly but if it covered mortgages as well that would be excellent.
I'd expect things like Mike links to will be off-line tools, ie you will need to type the data into them by hand.
If you are looking for some on-line thing that will log into your accounts automagically and present it all in one place, then I doubt such a thing exists, nor should it.
Firstly, there's the security implications of giving all your banking credentials to such an app, as has already been mentioned.
Secondly, most of the banks will require 2FA, so such an app won't be able to log in anyway without you having to respond to the multiple phone authentication requests or whatever, every time such an app tried to scrape fresh details.
Thirdly, all the institutions will have different web front ends and proprietary APIs for their own apps, there will be no consistency between them. Such an app would have no real way to navigate each bank's interface.