Welcome to cruise-chat.
I realize they place a tip at the end of each day on your account.
Actually, RCI does not do that. There are three ways to pay for tips on RCI. You can prepay them in full when you make the booking, you can have them added to you onboard account during the cruise, or you can use the traditional cash in envelopes on the last day of the cruise. In the second case they make one charge for all the tips and provide you with vouchers to put in the envelopes. It is really just a way to pay them without using a bunch of cash.
There is no need to hand out tips every day. The expectation of the crew is they will get rewarded on the last night of the cruise. I've never felt our service suffered because we didn't tip extra during the cruise. Some cruisers do believe in the greasing of palms for the cabin attendant and dining room staff on the first day. I don't.
There are exceptions.
Room service personnel should be tipped each time they bring an order. $2-5 depending on the size of the order. RCI charges a $3.95 room service fee for orders placed between midnight and 5am, and they say it includes the gratuity. I'd still add a bit to the ticket.
Although bar orders have 15% added to each order, I like to hand out cash to the staff at my favorite bars on the first day, and perhaps once or twice more on a 7 night cruise. In this case I do think it helps me get served quicker.
If you are on a ship with Chops or Portofino, the cover charge includes gratuities. Some still like to add a little more to the tab.
If your ship has a Johnny Rockets, the $4.95 cover charge includes tips. Again, if you feel like it you can add more.
However, it is my view that for your cabin and dining room staff it is fine to simply wait until the last night.
The RCI gratuity guidelines are located here