You do not need to install anything to work on your pronunciation. What you need has been on your phone for years.
How to do it
Open a search engine, type the word, press play, and then look away. Stop looking at the screen.
Reading the letters while you listen makes your brain cling to the spelling instead of attending to the actual sound. Once it has played, imitate it straight away, as closely as you can. It does not need to be perfect first time.
Why IPA made sense once, and does not now
IPA had a perfectly good reason to exist. Learners had no speakers and no recordings, so they relied on symbols to work out how something sounded. Rather like reading sheet music and imagining the melody in your head.
That is no longer the situation. You can hear any word, at any moment, for nothing. So there is no longer a case for learning IPA before you start listening.
The most effective method is not new
It is how a baby learns Vietnamese long before they can read. They hear adults speak and copy it. Hear it again, copy it again. And so on, until pronunciation is a completely natural reflex.
English, Italian, French, Chinese: every language can be learned this way, as long as you are not embarrassed to imitate the same thing over and over.
Practise more and you get better, and there is no shortcut around that, whatever method you choose.