I use this. I set up Fava served over my home network so my wife can look at the budget. There is an android app called Cone that lets you add entries. I sync between phone and PC with Syncthing. It all works really well.
But I only use that for cash or other things where I don't get a receipt. For the 99% I do get a receipt, I take a photo of said receipt. Then I deal with it later at my desktop or laptop where I have a real keyboard.
I actually wrote some helper script that works on top of Dired (in Emacs) to gather things like Payee and accounts using a completing-read (narrowing) style interface. This reduces friction A LOT, which I think is one of the keys to success in any chore.
