I've been window cleaning for about seven months now and have built up a reasonable round of nearly 260 houses.
I've heard of George, but can use a spreadsheet ok and have columns for dates I've cleaned, who owes me money and use a code so I can pull up houses by areas. You can also pull up houses by dates, so I don't think I need George yet. I spent about fifteen minutes a day updating my Window Register and printing out my daily work sheet.
However, the best bit of kit I've got is free! It's my missis. She'll only work 3 days a week, and then only during school hours (because of our brat being at school), but in 5 hours we can earn £100.00 without beasting ourselves.
She only cleans around quarter of what I do, complains when it's cold, wet or too hot, needs the toilet frequently (but will pee behind sheds if no-ones in) and only cleans ground floor windows and doors. But she helps setting up at each house (gets the bucket out, sorts out the clothes, hands me a shaken applicator (sponge T-Bar thingy), sexually harrasses me, collects the money, takes the A Frames and is good company (sometimes))!
I don't mean she's a thing, obviously she's a person, but she's my best bit of window cleaning kit!