I personally use HomeBank.
For French, Grammalecte is also nice. What I like about it is that I can very easily make it work with Emacs and AucTeX.
The app has an incredible UI ! It will be a good way to promote Lemmy to new users that mainly use the phone.
I use OpenBoard because I had an easier time (than with ASK) setting up a usable Bépo layout on it.