It is very annoying when you bought something useless from store.
PLEASE... make the store display clearly at the top of every product page :
C2 Runtime : Yes/No
C3 Runtime : Yes/No
3rd Plugins : Yes/No ( Yes : should mention what plugins and what runtime)
It is like throw you money in trash can when you buy something from scirra store which cannot be use because it contain 3rd plugin that does not support in certain runtime.
Sorry to say.. it just feel like scam!