Which service to use for delayed posting on Twitter?

Question

Computer networks

Free priority.
Necessary functions:
- the ability to import pictures attached to the post by url - bulk uploading of messages in the format " message
: url_images" (well, or excel)
on some channels, posts continue to hang in the delay, without going to the public.
The service support does not respond to this problem.
I would be glad for the links, while I continue to search.