This has happend twice now. I've sent btc to some one and the amount I send is sent in the right amount to the receiver but the balance of my wallet is emptied out in to another wallet following the chain. Can anyone explain why this would happen. I do understand there is a small transaction fee for the miner, but when it equals the balance of my wallet. Make me believe the android app developer  is scooping my balance.
I'm not happy about using this app anymore and have used it for many years with out a problem like this.. Any have this happen or know why or who is taking the balance?