Apps WhenI Use While Traveling Apps I Use While Traveling

There is nothing incorrect with your original title! This is just a stylistic change to add more context :)

Thanks to many mobile applications, it is easier to travel abroad now. Thanks to many mobile applications, it is easier to travel abroad now.

I uUsually, I use Google tTranslatore and Google mMaps. Usually, I use Google Translate and Google Maps.

What you wrote was correct but putting usually first is another way to write it

I usually use Google tTranslatore and Google mMaps. I usually use Google Translate and Google Maps.

As you may know, the translation app iss are very important for convenienteasy communication. As you may know, translation apps are very important for easy communication.

As you may know, thea translation app is very important for convenienteasy communication. As you may know, a translation app is very important for easy communication.

When I went to China, I could only say two sentences,phrases: "Nni Hhao" and "Xxie Xxie"." When I went to China, I could only say two phrases: "ni hao" and "xie xie."

Just fixed some punctuation choices here.

At thate time, there was no smart phonesmartphones weren't invented, so I couldn't enjoy the travelling. At the time, smartphones weren't invented, so I couldn't enjoy travelling.

You could also write "there were no smartphones at the time"

At that time, there was no smart phones, so I couldn't enjoy the travel. At that time, there was no smart phones, so I couldn't enjoy the travel.

Add s to make it plural meaning many

At that time, there was noI didn't have a smart phone at that time, so I couldn't enjoy the travelip. I didn't have a smartphone at that time, so I couldn't enjoy the trip.

At that time, there wasere no smart phones, so I couldn't enjoy the travelip. At that time, there were no smart phones, so I couldn't enjoy the trip.

The (nice) map app is useful during trips as well. The (nice) map app is useful during trips as well.

The nice map app is useful during trips as well. The map app is useful during trips as well.

The nice map app is nice and useful during trips as well. The map app is nice and useful during trips as well.

When I went to Warsaw in, Poland, I could visit beautiful small trails near the old town. When I went to Warsaw, Poland, I could visit beautiful small trails near the old town.

When I went to Warsaw in Poland, I couldwas able visit beautiful small trails near the old town. When I went to Warsaw in Poland, I was able visit beautiful small trails near the old town.

A natural way to say this

When I went to Warsaw in Poland, I couldwanted to visit beautiful small trails near the old town. When I went to Warsaw in Poland, I wanted to visit beautiful small trails near the old town.

At that time, the mGoogle Maps app helped me goguide me there. At that time, the Google Maps app helped guide me there.