I am not a very demanding user when it comes to screen capture applications. At first, I just need you to make them general, in a rectangular area or a specific window. It is true that annotations sometimes come in handy, so a recent addition to KDE's Spectacle tool comes in handy for me. Before that, when using Ubuntu / GNOME, I did my annotations in Shutter... until it disappeared from the official repositories.
Shutter is not an annotation app, but its editor has always seemed simple and efficient to me, so I installed the app when I could, which contributed to the fact that, unlike Spectacle, its editor allows you to open existing images. When Ubuntu removed it from its official repositories I was a bit orphaned, and even annotations with GIMP for a while, and as time passed I forgot about Shutter. Because of this, from my personal experience, I think Shutter 0.96 might be a bit late, but it never is if the bliss is good.
Shutter 0.96 switches to using GTK3
What happened with Shutter I think was a bit due to the sloppiness of its developers. It's been a couple of years since I told you about ksnip, which seemed like a good alternative to the Shutter that I missed so much. Two years ago of that article, but is that the removing the software from the official Ubuntu repositories It had already happened a long time ago, so it seems that they were resting on their laurels. In fact, Canonical even promoted Flameshot.
As mentioned, the problem was a security flaw, one that remained in GTK2, and one of the novelties included in Shutter 0.96 is that has made the leap to GTK3, so it is expected that sooner or later it will be able to be downloaded again from official repositories, and not using your snap package, which has some limitations, nor a third party repository.
As for other novelties, it seems that they are conspicuous by their absence, never better, since they have taken advantage of the moment to eliminate the option of choosing a portion of a window, something that was not used, and to fix some bugs.
Pending the more than likely return to the official repositories, users can install Shutter 0.96 from the Linux Uprising PPA (link above). In other distributions, such as those based on Arch Linux, it is already in AUR, and in this link there are instructions to install it on others like Fedora and Gentoo.