Some extra functionality that was mainly helpful for older dplyr versions can still be useful but is somewhat less relevant now:
mutate_rows mutate selected rows (see https://github.com/hadley/dplyr/issues/425)
Note 1: The function was originally called mutate_if.
It was renamed to mutate_rows since dplyr 0.5 introduced an own mutate_if function with quite
different behavior.
s_filter, s_arrange ,... allowing string arguments (see https://github.com/hadley/dplyr/issues/333)
To install in R, first install the package devtools from CRAN and then run
library(devtools);
install_github(repo="skranz/dplyrExtras")