I thought it was a problem with my phone since I’m using a custom ROM and it did not happen before. When I open Firefox and it has been in the background for a while, it shows a black screen where the web content should be and often crashes if you try to open another tab or do something else. Also happens if I open a link from another app. The only solution is to close Firefox and swipe it off the recent apps and reopen it. Is this the same problem you have?

I personally use Firefly-III. It is completely self-hosted (there is no cloud version that I know of), and is quite feature-complete. Their data importer allows you to import transactions directly from your bank (check if you bank is supported, but all European banks are), so you don’t need to create anything manually.

For example, I have the data importer running daily, and then I only have to set the correct category for each transaction, which doesn’t take that long.