Update: LaughingQuoll is actually not taking over the project, he merely wanted to help the community by fixing bugs and making it more stable. He has expressed regret in taking the project on, mentioning a lot of harassment over incompatible tweaks.
Apple can't make up their mind with notifications before iOS 10 we had the ability to sort notifications by app. After WWDC last year with the release of iOS 10, it seems as though they have forgone this option for users. As usual, there's is a jailbreak tweak for that! Unify, initially released by SpiritOfLogic (iRealSMS on Twitter), seeks to set things right with grouped notifications.
Its primary feature is to group your notifications by app, but he's packed a few other cool tricks in as well. You're able to choose whether or not to use Unify on the Lock Screen or Notification Center or both. You can also sort by App or Time, or turn off grouping all together.
A bonus feature that he added is message chaining. If somebody sends you a series of messages in succession, you won't get separate banners for each one. They will be 'chained' together in the same banner, each one appearing to the right of the next. This can be handy if you have 'friends' who love to spam your iMessage or WhatsApp.
After picking up the project LaughingQuoll dedicated a significant amount of time to optimise the code for performance and battery. Claiming users will see a 'dramatic increase' on Reddit.
It works well with Noctis, the dark colours showing nicely and playing well with the grouping. The Lock Screen notifications look good with the addition of the dark UI. It should work with most other tweaks that are affecting notifications, with a few exceptions.
ColorBanners 2 and Priority Hub are only partially supported right now. He is simply waiting for the developers of those tweaks to add support for Unify to their code. All of the issues are being tracked on his GitHub. If you have any problems with the tweak after installing, refer to the issues page or submit a new one if you don't see it listed.
If you aren't happy with the stock look of iOS's notifications, Unify X is for you. Whether or not you use it on the Lock Screen or Notification Center, your eyes will thank you. When you install it, the original version will be automatically uninstalled so there is no need to worry. Unify X can be found on the BigBoss for $2.00, and will be a free upgrade for people who purchased Unify originally.