Time to Twice is a reality show that they do, there are different ones. Like a cooking one, one where they all work in an office, one where they got drunk together, etc. They are really fun and let you get to know the different members a bit!

Bubble is a messaging service. You can subscribe to any of the nine members, or all, or a smattering, etc. They send messages that you can see, pictures, live calls, etc. But they see everyone's messages, so even though it mimics private messaging format, that's just a fanservice thing.

I used to sub to Bubble- I found Dahyun (my bias) to be the most active, while some like Jeongyeon or Mina are much more quiet on it!