WhatsHide

WhatsHide is an app that lets you read all the messages you receive on WhatsApp without needing to even access the app or the conversation itself, avoiding that dreaded double blue checkmark and without updating the time you were 'last seen.' This way, when the app is active, you get notified the instant you receive a new message, and can access a convenient interface where you can browse your conversations to read them without needing to open WhatsApp.

This app lets you avoid having to respond to someone who you don't want to give an answer to at a specific moment, and gives you a little breathing room, while your contacts think that you haven't even checked your phone in a while and may not any time soon.

If you want WhatsHide to stop notifying you about the arrival of new messages at any time, you just have to disable it from the settings menu and you'll automatically start receiving normal notifications from WhatsApp again.