How many weather apps are there in the application store of your smartphone? And how many virtual keyboards? And browsers? There are millions of clones out there but you are using that particular app and you don't want to change it. Why?
[ Laziness may be an answer, especially if you are a developer like me ;-) ]
Jokes aside, often I like to see if there are alternatives to the apps I use everyday. Sometimes I find good things but most of the time I keep using my old apps. So, which are the reasons for (not) changing? For me, mainly two: details and respect.
Usually the main feature is something that works pretty well in all clones. Any feed reader is supposed to let you read your favorite blogs. But only few let you have a customizable sharing button. It's a very small feature, a simple detail, but to me it's absolutely convenient.
But before trying a new app and evaluate its details, I check its permissions. I consider them a form of respect. Why do a weather app want to access my contacts? Why do a dictionary need to know to my position?
I know the answer: nothing is free. But this is a wrong answer. It would be different if the developer tells me: I need to access your GPS data in order to propose custom ads and keep the app free.
Maybe he is just bribing me but at least he don't think I'm so stupid to not understand that the permissions the app is asking for are not related to its features.