What's the ios app that gives you share options when you take a screenshot?
When you take a screenshot and the preview pops up in the bottom-left corner, just press and hold (for 1-2 seconds) on the preview. That will bring up the sharing panel right away.



Some additional details about screenshots if you're interested...

Any iOS app in the foreground can detect a screenshot and react however it wants. I guess you were using some app that offered helpful sharing when you took a screenshot of that app specifically, but I have no idea what that might have been.

There are no apps** that can change the system-wide behaviour of screenshots to reveal the sharing options when you take a screenshot. iOS apps can't interfere with the system that way.

**Actually that's not totally true. If you're trying pre-release versions of apps through TestFlight, any screenshots taken in the pre-release app are automatically converted to suggested feedback for the developer.