Hello!

I will cite a few examples for you:

One fateful day, I shared my experience with my friends who were tech geeks at that time, and they advised me to get an application called ”the noRoot firewall” from Google PlayStore which I did, and since then the amount of internet data used by my smartphone has reduced.

As I have said before, long and convoluted sentences affect comprehension, and lead to errors.

Let me rephrase for you: "One fateful day, I shared my experience with my friends who were tech geeks at that time, and they advised me to get an application called ”the noRoot firewall” from Google PlayStore, which I did, and since then the amount of internet data used by my smartphone has decreased/has been reduced."

Before I had difficulties managing the internet data on my Android device, I had an iPhone which I was using, and taking control over the applications which can access the Internet was made easy by the developers.

This sentence should read: "Before I started having difficulties managing the internet data on my Android device, I had an iPhone which I was using; therefore, taking control over the applications which could access the Internet was made easy by the developers."

Furthermore, I think that you need to do a better job with your paragraphing. The post contains too many short paragraphs, which makes it hard for the readers to get a flavour of the key points for the whole text. Your paragraphs should be between four to eight sentences long, and each paragraph should discuss one main, identifiable idea.

I hope you will find this comment useful.