Can I apply for UK standard visit visa from any place in the world? I'm an Egyptian citizen and would like to apply in Germany, France, Japan, etc...
You can apply as a visitor in any country that you entered legally AND has an Entry Clearance Issuing Post, and that would include Germany and just about anywhere else in the world.
This goes not just for Egyptians, but for anybody seeking a UK Standard Visitor Visa.
Apply on-line and submit your application to one of the Visa Application Centres near you.
For your specific case: It is doubtful, however, that you would qualify for expedited handling or fast-track processing because some nationals (Indian for example) are visa-nationals. Also, expect your application to be referred to the hub in Paris, which may add a day or two.
Based on the information at https://www.gov.uk/business-visitor-visa/apply, it appears that the answer is "yes." You apply online and then appear at a "visa application center" (sorry for the spelling, I'm American) to have your photograph and fingerprints taken. There is nothing to suggest that your nationality plays any role in the choice of location.