Grammar issues:

1)You can expect regular update to InstaBilling, based on your feedback" - Please pluralize update - (make it updates).

2)Timesheet made easy - Please pluralize timesheet - (make it timesheets)

3)Simply add your clients and tasks along with your hourly rate, and start tracking your time from everywhere. - Change everywhere to anywhere. You can't do ANYTHING from everywhere because you can only be in one place at a time.

Good luck - from your testimonials, it looks like you've got a good solution to a real pain point!