I've heard the dev is going to work full time on this project soon, is this truth? And that another dev is coming back?
Only if we manage to collect the necessary amount of
donations, so that JBG does not need his job any more and spend his full time on Spectre. He said that he needs about
60k XSPEC (or the equivalent in BTC, which would be roughly
5 BTC) so he can work full time on Spectre till the end of the year. So far, we have raised 22,500 XSPEC. I will donate some more XSPEC later, but if any of you could contribute BTC or also XSPEC that would be greatly appreciated. If we raise more than 5 BTC, he will be able to work fulltime even in 2018, and maybe an additional new developer will be hired.

You can find the donation addresses here:
https://spectreproject.io/donate/He also plans to integrate a feature into the wallet so that staking rewards (or a certain percentage thereof) can be donated automatically to fund development, which is a really cool idea IMO.