Thank you rdd0512 and hooover.
I went ahead and installed the apps without unlocking my phone; the installations were a success.
The Video enhancement app (the MJPEG version) gave me a slightly higher resolution option than the "L" option initially provided.
AFAIK, the BatteryHackOnly and the InternetSpeedHack have not made a significant difference, if any at all. Of course, that could be because they need to be cooked in, as you previouslly stated hooover.