Wachete is a free application available on Android that allows you to monitor changes on up to five web pages. You can select the whole page or just a part of it to monitor. The app sends email alerts and push notifications when the content of the web page changes.

Wachete collects data on its own servers, so you don't need to have your phone online to keep track of changes. The app also provides a history of content changes, complete with graphs for number values. You can set various rules for notifications, such as those that contain specific words or phrases, or those that show a growing trend.

In addition, Wachete also provides desktop widgets for quick information about web pages. You can use the app to monitor temperature, weather, headlines in the news portal, price of goods, and stock prices. Overall, Wachete is a useful tool for keeping track of changes on web pages, and it's completely free to use.