Just apps that need it; it's quite possible to have standalone apps that have no network requirements/permissions at all.
Often those that do require net connection but don't seem to justify it for the type of app they are, are 'free' apps that have ad banners. Depending on your phone type, the description for the app may well state why each of the permissions are needed (many reputable android apps will for example explain why their app needs this or that).