Yea chpwn originally released this but I'm not sure why r_plus updated it. I feel it's safe to install because r_plus is legit. I installed his SwipeShiftCaret tweak back on iOS 4 before swipeselection came out. I later switched to swipeselection because it was easier to swipe the keyboard instead of the text box. Plus I had issues when typing on this forum and also tying to swipe using swipeshiftcaret. Either way, I trust r_plus's stuff.
I think you're right though. I think all the tweaks from tweak week were open sourced on GitHub.
I don't know why iOS has such stiff scrolling. To reach the bottom of a thread here you'd have to swipe like 7 times. Now it takes only two or three. Just much better with a longer and quicker scroll speed.
Ah SwipeShiftCaret, that completely solidifies my faith in this dev. I loved dat on my iPad 3. Haven't figured out what I'm gonna do for that one quite yet on my rMini and possibly phone as well.