Short rest feature should be able to roll hit dice, automatically add the roll to health, and track that the hit dice is used. Right now its way to manual and the health and rest interfaces cover each other.

You should be able to tick a box for common buffs and debuffs and have them affect your rolls, e.g. bless, bane, poisoned.

Magic items like the Staff of Thunder and Lightning should add relevant actions and track their charges. Wand of Viscid Globs and the Tentacle Rod are more examples of this. I've had to homebrew spells to represent item powers to add to new versions of these items, and its annoying.

Different view options would be good e.g. sometimes you just want to see all your spells not everything else.

You should use the real estate of wide screen monitors better.

There should be a way to reroll the attack and damage of a persistent spell without it consuming a spell slot every time, e.g. attacking each round with Spiritual Weapon.

 You should be able to roll Tools by clicking on your tool proficiencies, not only from the equipment list.

Overall pretty happy with it, just needs some tweaks.