Instant messenger app for Android and iPhone

Question

Please find those criteria below. Thanks for any suggestion in advance!

must have features:

• it should be possible to exit/sign out from the app, so I have to write at least my password again (much better if I have to re-type my accountID too)
• possible to clear the chat history permanently
• adjustable push notifications
• both Android and iPhone version available
• no phone number required
• see online status OR get the delivery confirmed (it means at least that the app is running by the recipient)

would be great:

• as low as possible memory and battery drain footprint (compared to the other apps)
• windows desk version
• automatically sign out in the iPhone version if its swiped out from the running task

Answer 1

I like Trillian. It is very interoperable, integrates many different IM networks as well as having their own, and lets you connect or disconnect from each network independently.

The only thing I'm not certain of is whether it can be configured to prompt for a password when you connect. I generally protect the device and allow Trillian to keep my credentials for convenience. I don't think the Android app has an explicit exit function. You have to log out.

Answer 2

Try Threema (a seriously secure messaging app, their claim)

Your must-haves:

• Allows you to set up a PIN or system lock for app display
• You can clear chat messages
• Customizable notifications
• Android and iPhone Apps available
• Your identity is tied to a (self-maintained) private key, not a phone number
• No online status of other parties, but you see whether a message was delivered, and when it was seen.

Additionally:

• No idea about battery usage, but I never had a specific problem
• There is a web client available
• It's about 3$
• It has a strong focus to privacy and security

I use it personally, and I am very happy with it. However, it's not compatible with other solutions, so your partner will have to get it too.

Answer 3

Try Nimbuzz.

• It is possible to sign out and exit from it.
• We can clear history of each chat session whenever we want.
• Notifications can be pushed to corresponding accounts like facebook, google talk.(I don't get what you mean by adjustable)
• It got Android and iPhone version(also Windows, Blackberry, Nokia, Java and Kindle Fire).
• I think no phone number is required. We have to create our own ID during sign up.
• Absolutely, online status can be seen.
• It needs less battery when compared to most of the apps and less memory when compared to almost all other apps(not to all).
• It has a Windows desk version.
• Automatic sign out during its swipe out won't be available(I never tried it).