Melbourne app developer Long Zheng is on a mission. To "make myki great again".

To which some might reply: was it ever great?

But Mr Zheng is earnest, and genuinely wants to help. This week he released a free app that solves a key gripe for myki users: topping up using a mobile phone.

Despite it being 2017, Public Transport Victoria does not offer a mobile-friendly website for commuters to top up myki cards. The existing website forces users on phones to awkwardly tap, zoom, and input text in tiny fields.

"I use public transport every day, and so do my friends," Mr Zheng said. "They are always complaining about topping up, how hard it is to use the website. It would just be a whole lot easier if they could do it from the app.

"What you see on the mobile is the desktop webpage. It's quite difficult to zoom about and put text in the tiny fields."

Mr Zheng's app, mypal, makes it easy.

Users add their myki, allowing them to see their live balance. They can then tap a button to top-up on the go. The app does not add any additional functionality – it simply takes PTV's website and makes it mobile-friendly.

"What I'm doing is a mobile version of their site. What you do, what you look at, is all from the myki app," Mr Zheng said.

Unfortunately, top up isn't instant – it takes 90 minutes for PTV's servers to process a transaction and update a card. 

A spokesman for PTV said the department was working on reducing top-up processing time and building a mobile-friendly version of the myki top-up page.

At the moment mypal is only available for Android. Apple has refused to list it in its app store. Mr Zheng says he was told by Apple they would only authorise the app if it was officially supported by PTV.

Fairfax has revealed that commuters in so-called myki "dead zones" in some parts of Melbourne have to walk at least 1.5 kilometres to find a myki machine to top up.