On Android:

When creating and editing transactions, clicking on text fields such as Category, Payee, Notes, Tags and Account opens a pop-up dialog with a text field, but the keyboard is initially closed.

This means that you have to do an extra click into the text field to open up the keyboard and start typing. Would be great to have the keyboard automatically open up to speed things up.

Also, if the keyboard is open, you have to click twice to actually save changes (eg. Payee name) or select from the drop-down menu (eg. Categories). The first click on an item in the drop-down or the "Save" button closes the keyboard, and only the second click actually saves.