Whatsapp

Whatsapp is a popular messaging program for smartphones (you could say popularity is the most important feature of this type of programs). Someone described it as, it is to SMS as Skype is to voice calls. However, there are some very strange unsolved problems with it:

• Numerous security problems (see http://en.wikipedia.org/wiki/Whatsapp#Security_concerns) - ok fine, SMS isn't very secure in the first place.
• There's no way to sign out??? What kind of ridiculous design is this? So I have to be contactable all the time? Also, watch out about signing into another device - looks like the only way to remove your account from that device is to DELETE YOUR ACCOUNT.
• When you get a new message, it displays part of the message on your lock screen. When you try and view the message, it RE-DOWNLOADS the message. Why? Can't it download the message once it receives it? If it can display the message on the lock screen, why does it need to download it again? 
• Related, why does it sound 1 alert, then sound another when I open the app? I know I have new messages, that's why I'm checking.
• There is no way to see the nicknames of your contacts. Ok, there's half a way - when you get a message from them, the notification on the lock screen displays their nickname, not your contact name. So that's 2 problems: 1) cannot see nicknames of contacts 2) notification displays nickname instead of contact name
• In the group info page, it doesn't display nicknames
• If you scroll up to see an old message (like to look up an address), if you exit the chat, you'll lose your place and have to scroll again.