What is a good substitute for Kecap Manis
Kecap Manis is not simply sugar &amp; soy sauce, as there are spices, too.  (typically galangal (related to ginger) is one of them, which I've only found in the US in larger asian/international markets).

The Dutch spelling of Kecap Manis is Ketjap Manis and you can regularly find it available online  (Through Amazon, you can get Bango, Conimex, ABC and Jans).  

You can also find plenty of recipes for it (often intended for Indonesian or Dutch expats in America):


http://www.food.com/recipe/ketjap-manis-39318 :

1c. dark brown sugar, 1c. water, 1c. soy sauce, 7TB molasses, 1tsp fresh ginger, 1/2tsp corriander, 1/2tsp black pepper.  (see the link for instructions)
http://www.kayotic.nl/blog/ketjap-manis :

1/2c. soy sauce, 3TB molasses, 3TB brown or palm sugar, 1/4 a red chili pepper, 1 small garlic clove, 1" of ginger, 1 star anise (optional), some water.  (see link for instructions)
http://www.wikihow.com/Make-Kecap-Manis :

1c. soy sauce; 1c. brown sugar, palm sugar or molasses; 1/2c. water; 1" ginger or galagal (optional); 1 garlic clove (optional); 1 star anise (optional).  (do I have to keep saying 'see link'?)
https://food52.com/blog/16102-indonesia-s-favorite-condiment-how-to-make-and-use-it-yourself

1 part soy sauce, 1 part palm sugar (or brown sugar or molasses), flavorings (garlic, ginger, dried chiles, star anise, curry leaves).  (see link)
http://www.whats4eats.com/sauces/kecap-manis-recipe

1c. palm or brown sugar, 1c. soy sauce, 1/2c. water, 1 to 2 tsp molasses (optional), 1 or 2 slices galangal, 1 star anise.  (blah, blah)
http://www.eatingwell.com/recipe/248323/indonesian-sweet-soy-sauce-kecap-manis

1 1/4c. sugar, 1/2c. water, 10oz reduced sodium soy sauce, 1 star anise, 1 clove garlic.  (ditto)