Complete Reference for D&D

I'm trying to transfer my files to a Chromebook, but I'm having problems. I can't figure out how to make the app the default for opening .dd5 files. Has anyone figured how to do this in Chrome OS?

I bought the character manager a few days ago, and I'm pleasantly surprise so far. But I have a few concerns.

First, there's no support for Expertise. Perhaps there could be second checkbox after Proficiency. It would be grayed out and unclickable unless the Proficiency box was clicked.

Second ...

Yes, this is for the 5e app. Thanks for the quick reply!

I have downloaded all the official material I can find, and some of my homebrew classes as well. But when I try to import my custom items, I get an error message:
Failed to import data.table item has no column named app_id (code 1): , while compiling: INSERT or REPLACE into item(id,name,category ...

I'm trying to compile a list of magic items to give to my players eventually (through dungeons, merchants, etc). I have two items for each player (and potentially more) except two.

One is a half-elf valor bard who loves to collect animals (he currently has a bear, a longhorn ox, and a horse, with ...

The app has a bunch of different tags & filters for its content (spells have level, school, monsters have humanoid, undead), but I don't see any tags for races. I want to have custom races for a campaign I'm creating, and I'd like to see just those races. Is there any way to do this, and if not ...