Thanks for offering your app to us. However, in my opinion, I would not feel safe entrusting my own credentials to you as your app MAY contain malicious line of codes.
I'd rather write my log-in details on a piece of paper and store it somewhere else safe. Everyone! Think twice before handing in your log-in details and stuff. All things are possible in the internet. It may destroy your life for sure. 
My app has been approved by google, Google screens all the code before they publish it.
But never the less i understand you concern.