I suggest GPS Logger for Android (on Google Play). It is free and open source.

It can be set to log to a custom URL. This can be set to your own server, and can contain parameters for latitude/longitude, altitude, speed, accuracy etc. It can also contain a unique serial number for each Android device, so you can tell which phone is which.

It also supports logging to an OpenGTS server. OpenGTS is an open source project designed for tracking vehicles. So that could provide a web interface, with mapping etc.

GPS Logger has a number of options for how often to log, based on time or distance. Obviously higher frequency logging would use more data, and more battery power. It can also filter on accuracy, so it doesn't send any points if you don't have an accuracy GPS position.

I suggest GPS Logger for Android (on Google Play). It is free and open source.

It can be set to log to a custom URL. This can be set to your own server, and can contain parameters for latitude/longitude, altitude, speed, accuracy etc. It can also contain a unique serial number for each Android device, so you can tell which phone is which.

It also supports logging to an OpenGTS server. OpenGTS is an open source project designed for tracking vehicles. So that could provide a web interface, with mapping etc.

GPS Logger has a number of options for how often to log, based on time or distance. Obviously higher frequency logging would use more data, and more battery power. It can also filter on accuracy, so it doesn't send any points if you don't have an accurate GPS position.