WA LastSeen is an Android application developed by King TM LTD that allows you to monitor the activity of WhatsApp users. The app is free and falls under the category of Social & Communication. With WA LastSeen, you can keep an eye on the WhatsApp login and exit times of any number you monitor, and get detailed reports on how long they have spent on the app.

The app offers monthly, weekly, and hourly reports, and with different package options, you can add and track multiple phone numbers to your watch list. You can also name any mobile number you add, and the instant notifications feature will notify you as soon as the number you follow is active on WhatsApp. It is important to note that this application does not violate WhatsApp's privacy policy and terms of usage, nor does it hack accounts in any way.

Overall, WA LastSeen is a useful tool for parents who want to keep an eye on their children's WhatsApp activity, or for anyone who wants to monitor the activity of someone they know. The app is easy to use and provides accurate information on WhatsApp usage.