The other night, I wanted to message my girl to remind her of something, but didn't. Reason: I thought she might have forgotten to turn her mobile phone to "sleep" mode, and then wake up through the beep of my incoming message. (This has happened to most of us before, hasn't it?)
Strangely, this has been a problem ever since the days of ordinary text messages, but in 2017, messaging services like Whatsapp or Telegram still haven't tackled it. The solution would be so easy: Add an option to send a message SILENTLY so it won't make a sound (or even vibrate) on the receiving phone, regardless of their settings. Voila!
If you fancy this idea, why not email the messager service of your choice (or even all of them) - if enough users get on their nerves, they should eventually implement it, and if a smaller messenger service implements it (they are probably easier to convince), the larger ones are going to steal the feature anyway.
Reward: Whatsapp, if you do this, would you please do me a favor as well and stop blowing up my solitary emoticons to some obnoxious size - I hate that. Just makes everyone sending a single emoticon look like a douchebag. And if you think this is an essential "feature" of your messaging service (you probably do), at least make it optional for Christ sakes!