Like I said, it's my opinion and opinions can't be wrong, not disagreeing with you, just said isn't worth it to ME for that 5%. But if you are really THAT worried about having those last extra percentages for an emergency you should have a charger at work and in your car and leave it plugged in whenever you can(or even easier just carry an extra charged battery, and fill your gas tank on your way to work and on your way home cause you NEVER KNOW when you are going to need those last 100 drops of gas right? lol). Sorry not trying to make fun of it but we are talking about 5% of a battery :-\ You can also just buy an extended battery. Just seems to me there are so many more simple and more sane options than having to bump charge. Instead of doing those things you mentioned while bump charging you could be USING your phone while doing those things, except the shower I guess. Then charge your phone on the way to work or while at work. But I guess do whatever works for you. JUST MY OPINION
The "battery left" and all battery widgets/apps get their information on how much battery is "left" from the phone/battery itself(just doing a calculation of how much voltage the battery is putting out), something you can get yourself from the phone without those apps. It's all about how Lithium-Ion batteries charge and hold a charge; I won't get into how that "percentage" is calculated but do a Google search on lithium ion batteries and look at the legitimate research sites on the batteries (not forums) and it might be an eye opener for you on those percentages you are relying on :-) and just might change your mind on bump charging(probably not lol to each their own).
But anyway back to the original post, I think we can ALL agree that bump charging more than once is completely not worth it... right? lol