App to wake up WiFi periodically while on sleep

WiFi drastically drains the battery. There is a setting to disable WiFi while the phone is on sleep. However, it's all or nothing: either you are connected all the time (and kiss good-bye to the battery) or you receive notifications from WhatsApp only when you happen to turn on your phone, maybe next week. Is there **an app that would force the phone to connect to WiFi every, say, 10 minutes while on sleep**, for WhatsApp to check for new messages? This would both save the battery and permit receiving messages (almost) in real time. As a workaround, maybe the app could just wake up the phone every 10 minutes, though this is a bad solution. Preferably I would like a ready app, not a programming way of doing it -- I am not good at programming for Android.