There are two plans offered by Signal-a free plan and a pro plan. While I have upgraded to the pro-plan, I would wholeheartedly recommend the free plan to anyone wanting to test Signal out.
The free plan lets you schedule 3 tweets. This should give you a good baseline to establish whether Signal is the right tool for you.
The pro plan lets you schedule an unlimited amount of tweets, with intervals as short as eight hours apart. This means that if I schedule a tweet, I can have it tweeting as much as three times per day, indefinitely.
The nice thing is that the pro plan is very cheap compared to other auto-tweet software systems. Whereas most of the social media management tools will run you $100-$300 per month, Signal Pro is only $6.99 per month! For most writers, this is by far the biggest marketing impact you can have for such a relatively small amount of money. And it is a major time saver!