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

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

Apps WhenI 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.

I usually use Google tTranslatore and Google mMaps.

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

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

Just fixed some punctuation choices here.

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

The nice map app is useful during trips as well.

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

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

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

Add s to make it plural meaning many

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

A natural way to say this

I uUsually, I use Google tTranslatore and Google mMaps.

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

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

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

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

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

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