How reliable is the android phone app in particular Navigo Weekly Pass
1 answer
There's a fair amount of recent poor written reviews, although a very high "star" score on the Google Play store for the Android Paris Transport app. I think this means that for the majority of people the Android Navigo Pass app works well & reliably. And the written complaints about the app not working, are from the vocal minority where their phone hardware/Android implementation are not well supported.
The difficulty with Android is the vast array of hardware & implementations of Android/its versions. It's not feasible to test all possible combinations and some outlier phones will have a poor experience.
So, if your Android phone is a popular version and more recent, it would likely work fine.