Well this question is actually quite unique to my situation, at least with respect to my country Nigeria and I'll answer it with respect to Nigeria.
Now, we all know that oil is the raw material from which a significant number of products that we use today are created from, everything from the clothes we wear to our source of fuel and even some things that we use to cook are gotten from it and if the price of oil drops then obviously the price of these goods will drop as well.
A drop in crude oil prices is actually a good thing, at least for economic growth because less money will be spend on the oil industry and more money will be spent on other parts of the economy. On a microeconomic scale, basic things like drugs, petrol and any household item that is created from any oil based material will see it's price drop since the price of oil drops as well and this is actually good for the economy. On a macroeconomic scale a drop in the price of oil will also have a similar effect.
Taking about the Nigerian economy, it's not Far-fetched to say that the Nigerian Government gets about 70-90 percent of its yearly budget from the export of crude oil and when there are unexpected drops in the price of crude oil the government experiences serious budget deficits. These deficits send ripples through the economy which have a bit of an opposite effect on the economy than I previously explained.
I'm nigeria, the price of petrol is heavily subsidized by the government and over the years the fall in the price of crude oil has forced the government to reduce the amount t of subsidy which is accorded to petrol/diesel/kerosene etc. This has actually cause the economy to suffer because although the price of crude oil dropped, due to the reduction of the subsidy, the Nigerian people experienced a hike in the price of goods and services.
A drop in the price of crude oil positively affects the economies of other countries, but negatively affects that if Nigeria.
I hope this helps.