I don't use a website I do it by myself. For after school I do 1hr and 45 mins apart from on Fridays I do 45 mins. I focus on subjects I struggle in more than others. I do an hours revision in school with whatever subject they run that day, then I come home and do 15 mins of one subject then I take a break and do 45 minutes of another one. I do it this way so you are not restricted to times you just know you have to get that in somewhere in your night. As for the weekend and for the holidays I get up at 9am and start revision at 10am. I do 20 minutes of every subject with half an hour break in between. I find this works so well.
For example my weekend revision time table goes;
9;00-10:00 - Shower and Breakfast
10:0-10:20 - English Language
10:20-10:50 - BREAK
10:50-11:10- English Language
11:10-11:40- BREAK
11:40- 12:00 - Maths
12:00- 12:40 - LUNCH
12:40- 13:00 - Geography
13:00- 13:30 - BREAK
13:30- 13:50 - French
13:50- 14:20 - BREAK
14:20 - 14:40- Chemistry
14:40- 15:10 - BREAK
15:10- 15:30- Psychology
15:30- - 16:00 - BREAK
16:00 - 16:20 - Physics
16:20- 16:50 - BREAK
16:50- 17:10 - Biology
17:10-17:40 - BREAK
17:40- 18:00- Technology
18:00 - Tea and Free time...
You can mix this up to how it suits you, this is how I fit all my subjects in hope it helps