There needs to be a better way for friends and clanmates to communicate. I often have friends who come online and I wish I knew exactly when they did via a notification. I see they are in a battle and I invite them to a division. However, the battle they are in may be longer than 5 minutes and they will not see the invite.
1. Allow a notification to appear when one is in a battle that a friend has logged in. Make it both visual and audio (with the ability to mute, if necessary).
2. Allow for a brief message to the friend when in a battle.