The optimist classes is run and managed by IITians who have been among the toppers of various competitive examinations. Our mission is to provide quality learning platform to ensure good results. Our team leaders have proven track records. They have been teaching and guiding students for many years.

Make sure that third-party apps are allowed on your device: go to Menu->Settings->Security-> and check "Unknown Sources"

Tap the APK file. Allow the app any required permissions it asks for. Then, at the bottom of the installer window, click INSTALL.

You'll see a confirmation the app is installed. Now you'll see the app available in your list of installed apps.