I use Socialoomph primarily for scheduling content that can be repeated on a regular basis.It has a number of other features that are incredibly useful such as analytics, keyword tracking and viewing your mentions. You can have up to 5 accounts on it without upgrading although the pro version is reasonably priced and also allows you to manage your Linkedin and blogs as well as to post to your social media accounts through email.

It is not one of the most intuitive social media tools to use so expect to spend a little time finding your way around it., but once you have mastered it, you’ll find it well worth the effort.

http://www.socialoomph.co.uk
From USD14 per month if you choose the upgrade