App to track hours in each work site I'm a contractor and I visit my customer places, I would like to install an app that does automatically detect how much time I spend for a customer at which location with an ability to mark the project or client name.

In short I want a location based work log. Most of the apps currently require to clock-in or clock-out manually.
There are plenty of time tracking apps out there. Take a look at Time Clock for location-based work hours tracking: https://play.google.com/store/apps/details?id=co.timesquared.timetracker

You can also install Hours Tracker if you want an automatic clock in and clock out using preset GeoFences: https://play.google.com/store/apps/details?id=com.cribasoft.HoursTrackerFree.Android&amp;hl=en_US