Closed source? Get coins out, and uninstall. Don't support this. It goes against Bitcoin, as a movement, and as a philosophy.
i don't think people are using this wallet for "bitcoin", they use it for the very large number of altcoins that it supports which gives it an edge compared to other wallets.
otherwise if there existed any other wallet similar to Coinomi that supported this many altcoins AND were open source then i am sure nobody hesitated in switching to it.
Having a close source code is a big no for users who sees transparency to be one of the most important factor of success specially in the opensource community such as blockchain and linux. I did have a Coinomi wallet installed in my phone but never did I got a chance to use it because my mind is fixed on electrum on desktop and ETH on myetherwallet.
We don't really know if they got the copy of our privatekeys and we can only be sure about it if we see the codes.