What? I think you've heavily confused sideloading with jailbreaking. The apps don't disappear after you reboot. You just have to have it refresh every 7 days. With SideStore you don't even need another computer to do stuff. It's convenient as long as you don't need more than 2 other apps. You do NOT need to jailbreak to sideload. If you jailbreak, you can "sideload" infinite apps.