Still no contacts sync?
GrayHatter has implemented a prototype and will deliver a design document for the full implementation likely by the end of Q4. It includes profile and contact sync as well as message history sync. If we follow the intended timeline, that feature would likely land somewhere in 2017Q1. uTox and qTox have preliminary support for the prototype.
You and everybody else are invited to review the proposal when it comes out. Be sure to follow the issues on https://github.com/TokTok/c-toxcore/issues. You are also invited to join #toktok on Freenode to bounce ideas around.
Offline messaging will be partially solved by message log sync, as mentioned in milestone 4. The idea is that if you have a desktop computer at home, you could sync the message from your phone to it, and the desktop computer will deliver the message to your friend when they come online. It could be that your desktop syncs with their desktop at some point, and later their desktop syncs with their phone which is the actual delivery. In any case, this solution requires at least one of your and their devices to be online at one point. So far, we have shied away from storing large amounts of data in the network itself. I think the described solutions are sufficient for a large group of users. Federated (email-like) server-based (still distributed, just not p2p) solutions could be used for the remainder.
I see this "it's open source, make pull request" type of comment quite a lot but don't understand how you'd know if the person you're saying it to could do it. If not, it's kind of a dick move, isn't it?
Edit: here's a possibly better response than the "do it yourself" response:
XXX is a free and open source project. That means the developers put in the majority of their time on the issues that they want and enjoy coding the most, even if other good features are left out. If you're unable to help out with coding yourself, you could look through the open and closed issues and see of others have thought about your feature request too. If an open issue exists, a short "while I don't have the ability to code this, I'd like this feature too," added to the list would let the developers gauge interest and may sway someone into giving it a try. Thanks.
Edit 2: It's a bit long. This sentiment but shorter.
Okay, what about money? They also take donations.
> I see this "it's open source, make pull request" type of comment quite a lot but don't understand how you'd know if the person you're saying it to could do it. If not, it's kind of a dick move, isn't it?
No. Trying to make people feel bad for not wanting to work for free, is what I call a dick move.