The Calypso messenger bag by Cloudsplitter Bags is a must have for laptops, tablets, school bags or for anything else you can fit in them. I was able to participate in the testing of this beauty and I am in love with the bag pattern, I love all of Cloudsplitter Bags patterns. They are well written easy to understand and go together well. Sydney also has a facebook group for her pattern lovers. https://www.facebook.com/groups/560775854062664/?hc_location=ufi 
My 13 yr old daughter picked the fabrics for my tester bag, and claimed it for her school bag. I made the large size, which fits my 17" laptop perfectly, but there is a smaller size included in the pattern perfect for tablets, kindles and smaller items and is perfect for a kids bag. There is a hidden pocket in the flap perfect for carrying things like SD cards or jump drives. There is a large zipper pocket, and slip pockets for a cell phone, pens or whatever you would like to put in it. Plenty of padding to protect your computer or tablets without being super bulky. The flap is a fun design that keeps the messenger bag from being ordinary and plenty of options for customization. 
Right now this wonderful pattern is 50% off so please run over and grab it up right now! You won't be disappointed!http://www.craftsy.com/pattern/sewing/accessory/calypso-messenger-2-sizes-50-off/156293
Sizing / Finished Measurements:
- Small Bag (Tablet): 11" wide x 9" tall x 2" deep Large Bag (Laptop): 15.5" wide x11" tall x 2.5" deep
Materials:
- 1.5 yard Exterior main fabric (quilters cotton or similar)/ 1 yard for small
- 1.5 yard lining fabric (quilters cotton)/ 1 yard for small
- Soft and Stable sew in foam stabilizer (may also use Pellon Shape Flex FF77 by the yard):: 20" x58" (a bit less than 1 pack) S&S (or 1.5 yard x 20" FF77)/Piece 16"x45" S&S for SMALL (or 1.25 yardx20" FF77)
- 3 yard lightweight-mid-weight fusible interfacing (such as Pellon SF101/ Pellon 931td)/2.5yard small
- 1/4 yard Pellon 71f fusible bag stabilizer
- 1/2 yard contrasting fabric for piping if making your own piping
You Will Also Need:
- 1 magnetic snap (preferably a medium-large size)
- 2 metal D-rings, O-rings, or square rings 1.5" wide
- One 1.5" tri-glide slider or buckle slide (for an adjustable strap)
- 4 yards 1/8"-1/4" piping cord (or pre-made piping)/ 3 yards for small
- For SMALL tablet size bag: 1 4" nylon zipper for secret flap pocket 1 11" or longer nylon zipper for zip-slip front pocket
- For LARGE laptop size bag: 1 6" nylon zipper for secret flap pocket 1 16" or longer nylon zipper for front zip-slip pocket
