Use APKPure App
Get Snist - Web old version APK for Android
This is the android app of Sreenidhi official website which takes less than 2Mb.
This is the android app of Sreenidhi official website where you can do everything same as in website.You can check your marks,attendance,notifications,important dates etc., This is the lite version where it takes 2mb to download and around 7mb after installation.