Rebump is a business and enterprise application that helps professionals keep their messages in the front line of their recipients' inboxes. It automatically bumps messages up to the top of their recipients' inboxes at an interval of the user's choice. This can help users ensure that their important messages are not lost in their recipients' email clutter. It also allows users to customize the frequency of their bumps, so that the most important messages are bumped more often. Rebump also offers a range of analytics, such as tracking when messages are opened, and providing insights into the effectiveness of different bump strategies.
There is NOT much difference in their offers.
Saleshandy elegant interface
E-mail tracking with e-mail tracking
Faster creation and customization of tracking and tracing.
Automated tracking is better from SalesHandy