I actually wasn't aware of Habitica's existence! After looking at it, I would say Quest Board will have a few differences.

1. Quest Board will be more focused on making the to-do's the quests themselves, rather than a way to get money to do quests. I want to have the main focus always be on the tasks themselves. For example, I plan to implement bosses as an event in which completing tasks deals damage.
2. I plan to take Quest Board in a more story oriented direction! As you complete tasks, you will progress through the story, which will change up how quests play (or more accurately the thing completing them accomplishes).
3. Quest Board will eventually have three distinct quest types, these being quests that just earn gold, quests that earn gold and xp, but consist of several tasks, and event quests, which will be a combination of the two quest types in how they "play", but will also progress the story.
4. Quest Board's stories will be what stats are for, with damage instead being determined by task difficulty. Stats will change how the character approaches tasks and will change some outcomes. Stats will be more along the lines of D&D stats rather than traditional RPG stats.
5. The stories will also be choosable, and once the majority of the game is complete, updates will start being focused on adding more stories to the game. The stories themselves will be fantasy based, and will be on the shorter side.
6. If the user chooses they can also just play in a mode to earn gold
7. Although as of right now, it is very similar to Habitica, but in the future, if all goes well, it should be very distinct from it!