PHStat2 is a statistics add-in for Microsoft Excel. It makes using Excel easier for statistical operations. All statistical methods taught in an introductory statistics course can be done in Excel using the add-in along with the Data Analysis Tool Pack (that comes with Excel.)
Version 3.0 of the program includes Paired t Test, Pooled-Variance t Test Procedure for un-summarized data added, Separate-Variance t Test, etc.
PHStat2 is available with selected textbooks and myStatLab courses from Pearson. The download link is for update(2.8.1) to the program.