There aren’t many Catholic apps or themes for my Blackberry, and just started making wallpapers for mine.
So far I have 2 Sacred and Immaculate Hearts, and one Mater Dolorosa (for lent). You can view them here: s24.photobucket.com/albums/c46/miserissima/
If you tell me what kind of phone you have and what image you’d like as a background, I’d be glad to make some (free) wallpapers for you. Pick a saint or a devotion and let’s see what we can come up with. Just post here or PM me.