[frossie]

Yes there is an app, it is simple enough to allow you to tick off tasks, not much else.

There is an API, and I did see integrations with other to-do systems start to pop up.

http://habitrpg.wikia.co/wiki/App_and_Extension_Integrations

I was quite excited to see a discussion about tying in with Trello.

Code is on guthub.

[thameera]

Correct link: http://habitrpg.wikia.com/wiki/App_and_Extension_Integration...

[pigeons]

the above link should be for wikia.com it seems.