"The Chemist" (রসায়নবিদ) is an app for mastering chemical reactions with fun and visual presentations. You just need to write 2/3 letters and the app will provide a list of possible reactions for you.
There is an extensive list of chemical elements(2500+) alphabetically sorted out from which you click and select elements and thus build your reactions very easily. Each reaction un the app is visually presented and directly linked with Google . You can click the reaction as a whole or each element of the reaction individually to get highly informative videos to make your learning more interesting.