It's possible to continue to use ack.vim with
ag installed, but ag.vim supports the features
ag has that
ack doesn't. If you look at the ag.vim documentation, you'll see the extended options that it supports.
WakaTime is a time tracking service that has Vim support (GitHub: wakatime / vim-wakatime). Once you've installed it time will be tracked automatically -- the current project is derived from Git. You can also sign in at WakaTime to configure how projects are recognised.
The Vim support is provided by Python plugin, so technically many editors can work with WakaTime. There are also plugins for Emacs and Sublime.